LeetCode-Maximal Rectangle[code]

code:

#include <iostream>
#include <vector>
#include <stack>
#include <algorithm>
using namespace std;

class Solution {
public:
    int largestRectangleArea(vector<int> &height) {
        height.push_back(0);
        int i = 0;
        int result = 0;
        stack<int> s;
        while (i < height.size())
        {
            if (s.empty() || height[i]>height[s.top()])
                s.push(i++);
            else
            {
                int tmp = s.top();
                s.pop();
                result = max(result, height[tmp] * (s.empty() ? i : i - s.top() - 1));
            }
        }
        return result;
    }

    int maximalRectangle(vector<vector<char> > &matrix) {
        if (matrix.size() == 0 || matrix[0].size() == 0) return 0;
        int H = matrix.size(), W = matrix[0].size();
        int ret = 0;

        int **tmpHeight = new int*[H];
        for (int i = 0; i < H; i++)
        {
            tmpHeight[i] = new int[W];
        }

        for (int i = 0; i < H; i++)
        {
            for (int j = 0; j < W; j++)
            {
                if (matrix[i][j] == '0')
                {
                    tmpHeight[i][j] = 0;
                }
                else
                {

                    tmpHeight[i][j] = (i == 0 ? 1 : tmpHeight[i - 1][j] + 1);
                }
            }
        }
        for (int i = 0; i < H; i++)
        {
            vector<int> vtmp(tmpHeight[i], tmpHeight[i] + W);
            ret = max(ret, largestRectangleArea(vtmp));
        }
        return ret;
    }
};

int main()
{
    vector<vector<char>> v;

    char a1[] = { '0', '1', '0', '1', '1'};
    char a2[] = { '0', '1', '1', '1', '0' };//要用'1'和'0'来赋值！因为是char数组！不能用1,0 !
    char a3[] = { '1', '1', '1', '1','1' };
    v.push_back(vector<char>(a1, a1 + 5));
    v.push_back(vector<char>(a2, a2 + 5));
    v.push_back(vector<char>(a3, a3 + 5));
    Solution s;
    cout << s.maximalRectangle(v) << endl;
    return 0;
    }