题目链接
42. 接雨水
思路分析
与程序员面试金典 面试题 17.21. 直方图的水量相同。
class Solution {
public:
int trap(vector<int>& height) {
std::ios::sync_with_stdio(false);
if(height.empty()) return 0;
int n = height.size();
vector<int> left(n), right(n);
left[0] = height[0], right[n - 1] = height[n - 1];
for(int i = 1; i < n; i++)
left[i] = max(height[i], left[i - 1]);
for(int i = n - 2; i >= 0; i--)
right[i] = max(height[i], right[i + 1]);
int res = 0;
for(int i = 0; i < n; i++)
res += min(left[i], right[i]) - height[i];
return res;
}
};