class Solution {
public:
    int leastBricks(vector<vector<int>>& wall) {
        int n = wall.size();
        int m;
        //vector<int> tmp;
        int tmp;
        map<int,int> mymap; //记录次数
        int maxt = 0; //记录最多次数
        for(int i = 0; i < n; i++){
            //tmp = wall[i];
            m = wall[i].size();
            tmp = 0;
            for(int j = 0; j < m-1; j++){
                tmp += wall[i][j];
                mymap[tmp]++;
                maxt = max(maxt, mymap[tmp]);
            }
        }
        //printf("%d\n", maxt);
        return n-maxt;
    }
};