Sort custom function

Define a two-dimensional array

vector<vector<int>> ret;

(1) Press two-dimensional array ret[i][1] The size of is arranged from large to small   

static bool cmp(vector<int> &m, vector<int> &n) {

        retutn m[1] > n[1];                        // Represents a two-dimensional array

}

 sort(ret.begin(), ret.end(), cmp)

(2) Press two-dimensional array ret[i][1] The size of is arranged from small to large   ( Force buckle platform not used static Will make mistakes ,sort Request to static)

static bool cmp(vector<int> &m, vector<int> &n) {

        retutn m[1] < n[1];                        // Represents a two-dimensional array

}