상대오차, 백분율차 구하기

#include <iostream>
 
using namespace std;
 
int main(){
    cout << "0: relative error | 1: 백분율차" << '\n';
 
    int choose;
    cin >> choose;
    if(choose == 0){ // relative error
        int N;
        cin >> N;
        while(N--){
            double trueV, getV;
            cin >> trueV >> getV;
            double error = trueV - getV;
            cout << (error / trueV) * 100 << '%' <<'\n';
        }
    } else if(choose == 1){ // 백분율
        int N;
        cin >> N;
        while(N--){
            double v1, v2;
            cin >> v1 >> v2;
            double a;
            a = v1 - v2;
            if(a < 0) a = -a;
            cout << (a / ((v1 + v2) / 2)) * 100 << '%' << '\n';
        }
    }
    return 0;
}