Fixed points - P34682

#include <iostream>
#include <vector>
using namespace std;

bool find_fixed(vector<int>&v, int x, int&temp){
    int l = 0;
    int r = v.size()-1;
    while(r-l > 1){
        int m = (l+r)/2;
        if(v[m]+x >= m+1){
            r = m;
        }
        else{
            l = m;
        }
    }
    if(v[l]+x == l+1){
        temp = l;
        return true;
    }
    else if(v[r]+x == r+1){
        temp = r;
        return true;
    }
    else return false;
}

int main(){
    int n, j=1;
    while(cin>>n){
        vector<int> v(n,0);
        for(int i=0; i<n; ++i){
            cin>>v[i];
        }
        int m,x;
        cin>>m;
        cout<<"Sequence #"<<j<<endl;
        for(int i=0;i<m;++i){
            cin>>x;
            int temp;
            if(find_fixed(v,x,temp)){
                cout<<"fixed point for "<<x<<": "<<temp+1<<endl;
            }
            else cout<<"no fixed point for "<<x<<endl;
        }
        ++j;
        cout<<endl;
    }
}