UVa 11991

map演示

#include <stdio.h>#include <vector>#include <map>using namespace std;map<int, vector<int> > a;int main() {    int n, m, x, y;    while (scanf("%d%d", &n, &m) == 2) {        a.clear();        for (int i=0; i<n; i++) {            scanf("%d", &x);            if (!a.count(x))                a[x] = vector<int>();            a[x].push_back(i + 1);        }        while (m--) {            scanf("%d%d", &x, &y);            if (!a.count(y) || a[y].size() < x)                printf("0\n");            else                printf("%d\n", a[y][x - 1]);        }    }    return 0;}