Thread: i have problem in finishing my code

Code:

this program finds the largest multiple of 5 in a randomly generated  Vector of 20 elements and returns it as well as its index. but What  would biggest() return if none of the integers in the vector<> are  multiple of five? and how can i correct it?


#include <iostream>
#include <algorithm>
#include <vector>
#include <fstream>
using namespace std;
int biggest(vector<int>);
const int k=20;
int main()
{
    ofstream fout("pasuxi.out");
    vector <int> v(k);
    for(int i=0; i<k; i++)
        v[i]=rand() % 71+30;
    fout<<"biggest is  "<<v[biggest(v)]
        <<".    index=  "<< biggest(v);
}
int biggest(vector<int> x)
{
    int big=-1;
    int index;
    for(int i=0; i<x.size(); i++)
        if(x[i]%5==0 && x[i]>big){ 
            index=i;}
    return index;
}