UVA 11991 Easy Problem from Rujia Liu?

大意略。

原来map可以插vector额。

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