cses day1 problems solutions

missing_number.cpp

#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <algorithm>

using namespace std;

typedef long long ll;

void solution(){
    int n;
    cin >> n;
    int arr[n-1];
    for(int i=0; i<n-1; i++){
        cin >> arr[i];
    }
    sort(arr, arr+(n-1));
    bool flag = true;
    for(int i=0; i<n-1; i++){
        if(i+1!=arr[i]){
            cout << i+1 << endl;
            flag = false;
            break;
        }
    }
    if(flag){
        cout << n << endl;
    }

}

int main() {
    int T=1;
    // cin >> T;
    for(int t=0; t<T; t++) {
        solution();
    }
    return 0;
}