water problem

jhideki · jhideki · commit 72422d7359c6 · 2024-02-16T16:56:05.000-08:00
diff --git a/src/main.rs b/src/main.rs
@@ -1,9 +1,7 @@
-mod car_fleet;
-use car_fleet::Solution;
-
+mod trapping_rain_water;
+use trapping_rain_water::Solution;
 fn main() {
-    let position = vec![10, 8, 0, 5, 3];
-    let speed = vec![2, 4, 1, 1, 3];
-    let result = Solution::car_fleet(12, position, speed);
+    let heights = vec![0, 1, 0, 2, 1, 0, 1, 3, 2, 1, 2, 1];
+    let result = Solution::rain_water(heights);
     print!("{:?}", result);
 }
diff --git a/src/trapping_rain_water.rs b/src/trapping_rain_water.rs
@@ -0,0 +1,33 @@
+pub struct Solution {}
+impl Solution {
+    pub fn rain_water(height: Vec<i32>) -> i32 {
+        let mut rp: usize = height.len() - 1;
+        let mut lp: usize = 0;
+        let mut max_left: i32 = height[lp];
+        let mut max_right: i32 = height[rp];
+        let mut water: i32 = 0;
+        while rp > lp {
+            if height[rp] > height[lp] {
+                let vol = max_left - height[lp];
+                if vol > 0 {
+                    water += vol;
+                }
+                lp += 1;
+                if height[lp] > max_left {
+                    max_left = height[lp];
+                }
+            } else {
+                let vol = max_right - height[rp];
+                if vol > 0 {
+                    water += vol;
+                }
+                rp -= 1;
+                if height[rp] > max_right {
+                    max_right = height[rp];
+                }
+            }
+        }
+
+        water
+    }
+}
