Codility -- Frog-River-One

// you can also use includes, for example:// #include <algorithm>int solution(int X, vector<int> &A) {    // write your code in C++98    int n = A.size();    if(X<=0) return 0;        vector<bool> dis(n+1, false);        int i,j;    int count=0;    for(i=0; i<n && count<X; ++i)    {        if(A[i]>X || A[i]<=0) continue;        if(!dis[A[i]])        {            ++count;            dis[A[i]]=true;        }    }    if(count>=X) return i-1;    return -1;}