题解 | #找x#
找x
https://www.nowcoder.com/practice/069e2130430c41229ab25e47fa0949a6
#include <bits/stdc++.h>
using namespace std;
int main(){
int n,x,f;
while(cin>>n){
map<int,int> mp;//输入的数各不相同，故可用映射
for(int i=0;i<n;i++){
cin>>x;
mp[x] = i;
}
cin>>f;
if(mp.find(f)!=mp.end())
cout<<mp[f]<<endl;
else{
cout<<-1<<endl;
}
}
return 0;
}
