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feat: add solutions to lc problem: No.1507
No.1507.Reformat Date
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‎solution/1500-1599/1507.Reformat Date/README.md

Lines changed: 46 additions & 32 deletions
Original file line numberDiff line numberDiff line change
@@ -54,7 +54,11 @@
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<!-- 这里可写通用的实现逻辑 -->
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切分 `date` 字符串，获取对应的 `year`, `month`, `day`，然后拼接起来即可。
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**方法一：模拟**
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将字符串按空格分割为三个部分，分别为 `day`、`month` 和 `year`，然后拼接为 `YYYY-MM-DD` 的格式。
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时间复杂度 $O(1)$，空间复杂度 $O(1)$。
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<!-- tabs:start -->
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@@ -65,26 +69,12 @@
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```python
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class Solution:
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def reformatDate(self, date: str) -> str:
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months = [
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"Jan",
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"Feb",
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"Mar",
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"Apr",
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"May",
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"Jun",
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"Jul",
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"Aug",
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"Sep",
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"Oct",
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"Nov",
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"Dec",
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]
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mapper = {v: str(k + 1) for k, v in enumerate(months)}
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split = date.split(' ')
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year = split[2]
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month = mapper.get(split[1])
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day = split[0][: len(split[0]) - 2]
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return year + '-' + month.zfill(2) + '-' + day.zfill(2)
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s = date.split()
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s.reverse()
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months = " JanFebMarAprMayJunJulAugSepOctNovDec"
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s[1] = str(months.index(s[1]) // 3 + 1).zfill(2)
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s[2] = s[2][:-2].zfill(2)
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return "-".join(s)
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```
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### **Java**
@@ -94,21 +84,45 @@ class Solution:
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```java
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class Solution {
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public String reformatDate(String date) {
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Map<String, Integer> mapper = new HashMap<>();
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String[] months
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= {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
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for (int i = 0; i < months.length; ++i) {
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mapper.put(months[i], i + 1);
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}
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String[] split = date.split(" ");
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int year = Integer.parseInt(split[2]);
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int month = mapper.get(split[1]);
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int day = Integer.parseInt(split[0].substring(0, split[0].length() - 2));
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return String.format("%d-%02d-%02d", year, month, day);
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var s = date.split(" ");
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String months = " JanFebMarAprMayJunJulAugSepOctNovDec";
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int day = Integer.parseInt(s[0].substring(0, s[0].length() - 2));
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int month = months.indexOf(s[1]) / 3 + 1;
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return String.format("%s-%02d-%02d", s[2], month, day);
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}
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}
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```
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### **C++**
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```cpp
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class Solution {
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public:
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string reformatDate(string date) {
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string months = " JanFebMarAprMayJunJulAugSepOctNovDec";
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stringstream ss(date);
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string year, month, t;
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int day;
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ss >> day >> t >> month >> year;
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month = to_string(months.find(month) / 3 + 1);
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return year + "-" + (month.size() == 1 ? "0" + month : month) + "-" + (day > 9 ? "" : "0") + to_string(day);
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}
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};
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```
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### **Go**
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```go
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func reformatDate(date string) string {
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s := strings.Split(date, " ")
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day, _ := strconv.Atoi(s[0][:len(s[0])-2])
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months := " JanFebMarAprMayJunJulAugSepOctNovDec"
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month := strings.Index(months, s[1])/3 + 1
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year, _ := strconv.Atoi(s[2])
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return fmt.Sprintf("%d-%02d-%02d", year, month, day)
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}
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```
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### **...**
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```

‎solution/1500-1599/1507.Reformat Date/README_EN.md

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Original file line numberDiff line numberDiff line change
@@ -58,48 +58,58 @@
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```python
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class Solution:
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def reformatDate(self, date: str) -> str:
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months = [
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"Jan",
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"Feb",
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"Mar",
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"Apr",
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"May",
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"Jun",
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"Jul",
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"Aug",
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"Sep",
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"Oct",
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"Nov",
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"Dec",
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]
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mapper = {v: str(k + 1) for k, v in enumerate(months)}
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split = date.split(' ')
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year = split[2]
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month = mapper.get(split[1])
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day = split[0][: len(split[0]) - 2]
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return year + '-' + month.zfill(2) + '-' + day.zfill(2)
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s = date.split()
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s.reverse()
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months = " JanFebMarAprMayJunJulAugSepOctNovDec"
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s[1] = str(months.index(s[1]) // 3 + 1).zfill(2)
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s[2] = s[2][:-2].zfill(2)
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return "-".join(s)
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```
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### **Java**
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```java
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class Solution {
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public String reformatDate(String date) {
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Map<String, Integer> mapper = new HashMap<>();
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String[] months
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= {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
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for (int i = 0; i < months.length; ++i) {
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mapper.put(months[i], i + 1);
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}
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String[] split = date.split(" ");
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int year = Integer.parseInt(split[2]);
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int month = mapper.get(split[1]);
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int day = Integer.parseInt(split[0].substring(0, split[0].length() - 2));
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return String.format("%d-%02d-%02d", year, month, day);
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var s = date.split(" ");
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String months = " JanFebMarAprMayJunJulAugSepOctNovDec";
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int day = Integer.parseInt(s[0].substring(0, s[0].length() - 2));
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int month = months.indexOf(s[1]) / 3 + 1;
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return String.format("%s-%02d-%02d", s[2], month, day);
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}
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}
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```
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### **C++**
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```cpp
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class Solution {
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public:
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string reformatDate(string date) {
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string months = " JanFebMarAprMayJunJulAugSepOctNovDec";
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stringstream ss(date);
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string year, month, t;
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int day;
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ss >> day >> t >> month >> year;
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month = to_string(months.find(month) / 3 + 1);
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return year + "-" + (month.size() == 1 ? "0" + month : month) + "-" + (day > 9 ? "" : "0") + to_string(day);
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}
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};
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```
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### **Go**
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```go
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func reformatDate(date string) string {
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s := strings.Split(date, " ")
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day, _ := strconv.Atoi(s[0][:len(s[0])-2])
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months := " JanFebMarAprMayJunJulAugSepOctNovDec"
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month := strings.Index(months, s[1])/3 + 1
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year, _ := strconv.Atoi(s[2])
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return fmt.Sprintf("%d-%02d-%02d", year, month, day)
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}
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```
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### **...**
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```

‎solution/1500-1599/1507.Reformat Date/Solution.cpp

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,12 @@
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class Solution {
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public:
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string reformatDate(string date) {
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string months = " JanFebMarAprMayJunJulAugSepOctNovDec";
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stringstream ss(date);
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string year, month, t;
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int day;
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ss >> day >> t >> month >> year;
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month = to_string(months.find(month) / 3 + 1);
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return year + "-" + (month.size() == 1 ? "0" + month : month) + "-" + (day > 9 ? "" : "0") + to_string(day);
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}
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};

‎solution/1500-1599/1507.Reformat Date/Solution.go

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,8 @@
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func reformatDate(date string) string {
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s := strings.Split(date, " ")
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day, _ := strconv.Atoi(s[0][:len(s[0])-2])
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months := " JanFebMarAprMayJunJulAugSepOctNovDec"
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month := strings.Index(months, s[1])/3 + 1
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year, _ := strconv.Atoi(s[2])
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return fmt.Sprintf("%d-%02d-%02d", year, month, day)
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}

‎solution/1500-1599/1507.Reformat Date/Solution.java

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Original file line numberDiff line numberDiff line change
@@ -1,15 +1,9 @@
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class Solution {
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public String reformatDate(String date) {
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Map<String, Integer> mapper = new HashMap<>();
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String[] months
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= {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
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for (int i = 0; i < months.length; ++i) {
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mapper.put(months[i], i + 1);
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}
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String[] split = date.split(" ");
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int year = Integer.parseInt(split[2]);
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int month = mapper.get(split[1]);
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int day = Integer.parseInt(split[0].substring(0, split[0].length() - 2));
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return String.format("%d-%02d-%02d", year, month, day);
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var s = date.split(" ");
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String months = " JanFebMarAprMayJunJulAugSepOctNovDec";
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int day = Integer.parseInt(s[0].substring(0, s[0].length() - 2));
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int month = months.indexOf(s[1]) / 3 + 1;
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return String.format("%s-%02d-%02d", s[2], month, day);
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}
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}

‎solution/1500-1599/1507.Reformat Date/Solution.py

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Original file line numberDiff line numberDiff line change
@@ -1,22 +1,8 @@
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class Solution:
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def reformatDate(self, date: str) -> str:
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months = [
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"Jan",
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"Feb",
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"Mar",
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"Apr",
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"May",
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"Jun",
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"Jul",
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"Aug",
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"Sep",
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"Oct",
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"Nov",
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"Dec",
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]
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mapper = {v: str(k + 1) for k, v in enumerate(months)}
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split = date.split(' ')
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year = split[2]
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month = mapper.get(split[1])
21-
day = split[0][: len(split[0]) - 2]
22-
return year + '-' + month.zfill(2) + '-' + day.zfill(2)
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s = date.split()
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s.reverse()
5+
months = " JanFebMarAprMayJunJulAugSepOctNovDec"
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s[1] = str(months.index(s[1]) // 3 + 1).zfill(2)
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s[2] = s[2][:-2].zfill(2)
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return "-".join(s)

‎solution/1500-1599/1513.Number of Substrings With Only 1s/README.md

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Original file line numberDiff line numberDiff line change
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**方法一：遍历计数**
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我们遍历字符串 $s$，用变量 $cnt$ 记录当前连续的 1 的个数，用变量 $ans$ 记录答案。当遍历到字符 $s[i]$ 时，如果 $s[i] = 1$，则 $cnt$ 自增 1，否则 $cnt$ 置 0。此时，$ans$ 自增 $cnt$。
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我们遍历字符串 $s$，用变量 $cnt$ 记录当前连续的 1 的个数，用变量 $ans$ 记录答案。当遍历到字符 $s[i]$ 时，如果 $s[i] = 1$，则 $cnt$ 自增 1，否则 $cnt$ 置 0。此时 $ans$ 自增 $cnt$。
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63-
最后，返回 $ans$ 即可。
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遍历结束，返回 $ans$ 即可。
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时间复杂度 $O(n)$，空间复杂度 $O(1)$。其中 $n$ 为字符串 $s$ 的长度。
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