uva 11991 Easy Problem from Rujia Liu?

题目：Easy Problem from Rujia Liu?

思路：略。

代码：

#include<cstdio>#include<stack>#include<algorithm>#include<queue>#include<deque>#include<iostream>#include<map>using namespace std;map<int,vector<int> > mp;int n,m;int main() {while(~scanf("%d%d",&n,&m)){mp.clear();for(int i=1;i<=n;i++){int x;scanf("%d",&x);mp[x].push_back(i);}for(int i=1;i<=m;i++){int x,y;scanf("%d%d",&x,&y);vector<int> a=mp[y];if(a.size()>=x) printf("%d\n",a[x-1]);else printf("0\n");}}return 0;}