समस्या
Bars of width 1 have the given heights. After rain, water collects above each bar up to the lower of the tallest bars on its left and right. Compute the total trapped water. An O(n) two-pointer solution is expected.
Implement trapped_water(heights).
Input
heights: Bar heights from left to right.
Output
Return the total units of water.
सीमाएँ
0 ≤ length ≤ 200,000; 0 ≤ height ≤ 100,000
उदाहरण
उदाहरण 1
इनपुट:
heights = [0, 1, 0, 2, 1, 0, 1, 3, 2, 1, 2, 1]
अपेक्षित आउटपुट:
expected = 6इनपुट:
std::vector<long long> heights = {0, 1, 0, 2, 1, 0, 1, 3, 2, 1, 2, 1};
अपेक्षित आउटपुट:
long long expected = 6;इनपुट:
long[] heights = new long[] {0, 1, 0, 2, 1, 0, 1, 3, 2, 1, 2, 1};
अपेक्षित आउटपुट:
long expected = 6;व्याख्या
Water fills the dips: 1 + 1 + 2 + 1 + 1 = 6 units.
उदाहरण 2
इनपुट:
heights = [3, 2, 1]
अपेक्षित आउटपुट:
expected = 0इनपुट:
std::vector<long long> heights = {3, 2, 1};
अपेक्षित आउटपुट:
long long expected = 0;इनपुट:
long[] heights = new long[] {3, 2, 1};
अपेक्षित आउटपुट:
long expected = 0;व्याख्या
Heights only go down, so water runs off: 0.
संदर्भ
यह चुनौती CodeUtility के लिए अनुकूलित की गई है। ऊपर दिए गए स्टेटमेंट और सीमाओं का पालन करें।