c_cpp GFG重复和失踪

Posted 2021-05-14

#include <bits/stdc++.h>
using namespace std;

// #Searching #Problem #GFG
// https://www.geeksforgeeks.org/find-a-repeating-and-a-missing-number/

int main() {
	int t;
	cin>>t;
	while(t--){
	    int n;
	    cin>>n;
	    int x,y; // x-missing y-repeating
	    vector<int> a(n);
	    vector<int> count(n+1,0); // 0 to n
	    count[0]=-1; // 0 not included in problem
	    for(int i=0;i<n;i++){
	        cin>>a[i];
	        count[a[i]]++;
	        if(count[a[i]]==2){
	            y=a[i];
	        }
	    }
	    for(int i=1;i<n;i++){
	        if(count[i]==0){
	            x=i;
	        }
	    }
	    cout<<x<<" "<<y<<endl;
	}
	return 0;
}