Арифметическая прогрессия 2

#include <math.h>
#include <iomanip>
#include <iostream>
#include <string>
//#include <stack>
#include <stdio.h>
//#include <queue>
//#include <set>
//#include <time.h>
#include <vector>
#define pause system("pause")
using namespace std;
//setlocale(LC_ALL, "Russian");
//printf("%d ", x);
//scanf_s("%d", &x);

#include <ctime>
unsigned int start_time;
void begin_c() {
    start_time = clock(); // начальное время
}
void end_c() {
    unsigned int end_time = clock(); // конечное время
    unsigned int search_time = end_time - start_time; // искомое время
    cout << "Runtime = " << (double)search_time / 1000 << " seconds" << endl;
}

vector <int> a;
vector <int> help;

void mergerSort(int l, int r) {
    if (l < r) {
        int c = (l + r) / 2;
        mergerSort(l, c);
        mergerSort(c + 1, r);
        int i = l;
        int j = c + 1;
        int k = l;
        while (i <= c && j <= r) {
            if (a[i] <= a[j]) {
                help[k] = a[i];
                i++;
                k++;
            }
            else {
                help[k] = a[j];
                j++;
                k++;
            }
        }
        while (i<=c) {
            help[k] = a[i];
            k++;
            i++;
        }
        while (j <= r) {
            help[k] = a[j];
            k++;
            j++;
        }
        }
}

int main() {
    string s;
    getline(cin, s);
    int num = 0;
    int n = 0;
    for (int i = 0; i < s.length(); i++) {
        if (i == s.length()-1) {
            num *= 10;
            num += s[i] - '0';
            a.push_back(num);
            n++;
        }
        else {
            if (s[i] == ' ') {
                a.push_back(num);
                num = 0;
                n++;
            }
            else {
                num *= 10;
                num += s[i] - '0';
            }
        }
    }
    help.resize(a.size());
    mergerSort(0, n - 1);
    for (int i = 0; i < n; i++) printf("%d ", a[i]);
    cout << endl;
    int d = 0;
    d = a[1] - a[0];
    for (int i = 2; i < n; i++) {
        int del = a[i] - a[i - 1];
        if (del != d) {
            cout << "No" << endl;
            pause;
            return 0;
        }
    }
    cout << "Yes" << endl;
    pause;
    return 0;

    pause;
}