"Algorithm Notes" Finding Elements

Finding Elements

[Codeup 1934] find X

Enter a number n, and then enter the n value is different, then a value of input x, the output value in the array subscript (from 0, if the array is output 1).
Input
test data set multiple, input n (1 <= n <= 200), then the number of inputs n, and the input x.
Output
for each set of input, output.
Sample input
4
1 2 3 4
3
sample output
2
resolved: OJ seem bad, did not return a result, the current sample test correctly

#include<iostream>
#include<vector>
using namespace std;
int main(){
	int n;
	cin>>n;
	vector<int> v(n);
	for(int i = 0;i<n;++i) cin>>v[i];
	int m,flag=-1;
	cin>>m;
	for(int i=0;i<n;i++){
		if(v[i]==m) flag=i;
	}
	cout<<flag;
	return 0;
}