九度 1497：面积最大的全1子矩阵

#include <iostream>
#include <stdio.h>
#include <vector>
#include <deque>
#include <memory.h>
using namespace std;
int m, n;
int matrix[1001][1001];
int rectangle[1001];

int largestHis() {
    int global = 0;
    deque<int> stack;
    for(int i = 0; i < n; i ++) {
        if(!stack.size()) {
            stack.push_back(i);
        }else if(stack.back() <= rectangle[i]) {
            stack.push_back(i);
        }else {
            int hei = stack.back();
            stack.pop_back();
            int left = (stack.empty())? 0:rectangle[stack.back()];
            global = max(global, (i-left-1)*rectangle[hei]);
            i--;
        }
    }
    return global;
}

int main() {
    while(scanf("%d%d", &m, &n) != EOF) {
        for(int i = 0; i < m; i ++) {
            for(int j = 0; j < n; j ++) {
                scanf("%d", &matrix[i][j]);
            } 
        }
        memset(rectangle, 0, sizeof(rectangle));
        int global = 0;
        for(int i = 0; i < m; i ++) {
            for(int j = 0; j < n; j ++) {
                if(matrix[i][j] == 0) {
                    rectangle[j] = 0;
                }else{
                    rectangle[j] ++;
                }
                //cout << rectangle[j] << " ";
            }
            //cout << endl;

            global = max(global, largestHis());
        }
        cout << global << endl;
    }
    return 0;
}