uva 11991 - Easy Problem from Rujia Liu?
map的用法:
代码:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
1 #include<vector> 2 #include<cstdio> 3 #include<map> 4 #define maxn 1000009 5 using namespace std; 6 7 vector<int>ve[maxn]; 8 map<int,vector<int> >mp; 9 int n,m,x,y; 10 int main() 11 { 12 while(scanf("%d%d",&n,&m)!=EOF) 13 { 14 mp.clear(); 15 for(int i=0;i<n;i++) 16 { 17 scanf("%d",&x); 18 if(!mp.count(x))mp[x]=vector<int>(); 19 mp[x].push_back(i+1); 20 } 21 while(m--) 22 { 23 scanf("%d%d",&x,&y); 24 if(!mp.count(y)||mp[y].size()<x)puts("0"); 25 else printf("%d\n",mp[y][x-1]); 26 } 27 } 28 return 0; 29 }