一、视频讲解

蓝桥杯真题讲解：异或和之和 （拆位、贡献法）

二、正解代码

//拆位考虑
#include<bits/stdc++.h>
#define endl "\n"
#define pb push_back
#define deb(x) cout << #x << " = " << x << '\n';
#define INF 0x3f3f3f3f
#define int long long
using namespace std;

void solve()
{
	int n; cin >> n;
	vector<int>a(n);
	for(int i = 0; i < n; i ++){
		cin >> a[i];
	}
	int ans = 0;
	for(int i = 20; i >= 0; i -- ){
		int s = 0, n0 = 1, n1 = 0;
		for(int j = 0; j < n; j ++){
			int bit = (a[j] >> i) & 1;
			s += bit;
			if(s % 2){
				ans += (1 << i) * n0;
				n1 ++;
			}else{
				ans += (1 << i) * n1;
				n0 ++;
			}
		}	
	}
	cout << ans << endl;
}

signed main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int t = 1;
	//cin >> t;
	while(t--)
	solve();
}