[uva11991]map和vector的入门

 1 #include<cstdio>
 2 #include<cstdlib>
 3 #include<cstring>
 4 #include<iostream>
 5 #include<algorithm>
 6 #include<cmath>
 7 #include<vector>
 8 #include<map>
 9 using namespace std;
10 
11 map< int,vector<int> >  a;
12 
13 int main()
14 {
15     freopen("a.in","r",stdin);
16     freopen("a.out","w",stdout);
17     int n,m,x,k;
18     while(scanf("%d%d",&n,&m)!=EOF)
19     {
20         a.clear();
21         for(int i=1;i<=n;i++)
22         {
23             scanf("%d",&x);
24             if(!a.count(x)) a[x]=vector<int>();
25             a[x].push_back(i);
26         }
27         for(int i=1;i<=m;i++)
28         {
29             scanf("%d%d",&k,&x);
30             if(!a.count(x) || a[x].size()<k) printf("0\n");
31             else printf("%d\n",a[x][k-1]);
32         }
33     }
34     return 0;
35 }