7 problems solved.

lintcoder · lintcoder · commit b625037e9035 · 2021-10-30T20:59:56.000+08:00
diff --git a/src/1984.cpp b/src/1984.cpp
@@ -0,0 +1,16 @@
+int minimumDifference(vector<int>& nums, int k) {
+        if (k == 1)
+            return 0;
+        sort(nums.begin(), nums.end());
+        int len = nums.size();
+        int mindiff = 1e5;
+        
+        for (int i = len-1; i >= k-1; --i)
+        {
+            int diff = nums[i]-nums[i-k+1];
+            if (diff < mindiff)
+                mindiff = diff;
+        }
+        
+        return mindiff;
+    }
diff --git a/src/1995.cpp b/src/1995.cpp
@@ -0,0 +1,19 @@
+int countQuadruplets(vector<int>& nums) {
+        int len = nums.size();
+        int ct = 0;
+        
+        for (int i = 0; i < len-3; ++i)
+        {
+            for (int j = i+1; j < len-2; ++j)
+            {
+                for (int m = j+1; m < len-1; ++m)
+                {
+                    for (int n = m+1; n < len; ++n)
+                        if (nums[i]+nums[j]+nums[m] == nums[n])
+                            ++ct;
+                }
+            }
+        }
+        
+        return ct;
+    }
diff --git a/src/2016.cpp b/src/2016.cpp
@@ -0,0 +1,18 @@
+    int maximumDifference(vector<int>& nums) {
+        int len = nums.size();
+        int maxdiff = 0;
+        for (int i = 0; i < len-1; ++i)
+        {
+            for (int j = i+1; j < len; ++j)
+            {
+                int diff = nums[j]-nums[i];
+                if (diff > maxdiff)
+                    maxdiff = diff;
+            }
+        }
+        
+        if (maxdiff == 0)
+            maxdiff = -1;
+        
+        return maxdiff;
+    }
diff --git a/src/2022.cpp b/src/2022.cpp
@@ -0,0 +1,16 @@
+vector<vector<int>> construct2DArray(vector<int>& original, int m, int n) {
+        int len = original.size();
+        if (m*n != len)
+            return {};
+        
+        vector<vector<int>> res(m, vector<int>(n, 0));
+        for (int i = 0; i < m; ++i)
+        {
+            for (int j = 0; j < n; ++j)
+            {
+                res[i][j] = original[i*n + j];
+            }
+        }
+        
+        return res;
+    }
diff --git a/src/2032.cpp b/src/2032.cpp
@@ -0,0 +1,34 @@
+vector<int> twoOutOfThree(vector<int>& nums1, vector<int>& nums2, vector<int>& nums3) {
+        int arr[101][3];
+        memset(arr, 0, 303*sizeof(int));
+        int len1 = nums1.size();
+        int len2 = nums2.size();
+        int len3 = nums3.size();
+        for (int i = 0; i < 100; ++i)
+        {
+            if (i < len1)
+            {
+                if (arr[nums1[i]][0] == 0)
+                    ++arr[nums1[i]][0];
+            }
+            if (i < len2)
+            {
+                if (arr[nums2[i]][1] == 0)
+                    ++arr[nums2[i]][1];
+            }
+            if (i < len3)
+            {
+                if (arr[nums3[i]][2] == 0)
+                    ++arr[nums3[i]][2];
+            }
+        }
+        
+        vector<int> res;
+        for (int i = 0; i < 101; ++i)
+        {
+            if (arr[i][0] + arr[i][1] + arr[i][2] >= 2)
+                res.push_back(i);
+        }
+        
+        return res;
+    }
diff --git a/src/2042.cpp b/src/2042.cpp
@@ -0,0 +1,32 @@
+    bool areNumbersAscending(string s) {
+        int len = s.size();
+        int index = 0;
+        int pos = s.find(' ', index);
+        int lastnum = 0;
+        while (pos != string::npos)
+        {
+            if (isdigit(s[index]))
+            {
+                int sum = 0;
+                for (int i = index; i < pos; ++i)
+                    sum = 10*sum + (s[i]-'0');
+                if (sum <= lastnum)
+                    return false;
+                else
+                    lastnum = sum;
+            }
+            index = pos+1;
+            pos = s.find(' ', index);
+        }
+        
+        if (isdigit(s[index]))
+        {
+            int sum = 0;
+            for (int i = index; i < len; ++i)
+                sum = 10*sum + (s[i]-'0');
+            if (sum <= lastnum)
+                return false;
+        }
+        
+        return true;
+    }
diff --git a/src/2047.cpp b/src/2047.cpp
@@ -0,0 +1,49 @@
+int countValidWords(string sentence) {
+        auto first = sentence.begin();
+        auto last = sentence.end();
+        auto p = first, q = first;
+        auto func = [](char c){
+            return c == ' ';
+        };
+        
+        int ct = 0;
+        p = find_if_not(p, last, func);
+        q = find_if(p, last, func);
+        while (p != last && q != last)
+        {
+            if (isValid(sentence, p, q))
+                ++ct;
+            p = find_if_not(q, last, func);
+            if (p != last)
+                q = find_if(p, last, func);
+        }
+        
+        if (p != last && isValid(sentence, p, q))
+            ++ct;
+
+        return ct;
+    }
+    
+    bool isValid(const string& sentence, string::iterator& p, string::iterator& q)
+    {
+        int hyphennum = 0;
+        for (auto iter = p; iter != q; ++iter)
+        {
+            if (isdigit(*iter))
+                return false;
+            if (*iter == '-')
+            {
+                ++hyphennum;
+                if (hyphennum > 1)
+                    return false;
+                if (iter == p || iter == q-1)
+                    return false;
+                if (!isalpha(*(iter-1)) || !(isalpha(*(iter+1))))
+                    return false;
+            }
+            if ((*iter == ',' || *iter == '.' || *iter == '!') && (iter != q-1))
+                return false;
+        }
+        
+        return true;
+    }
