Lang:G++
Edit12345678910111213141516171819202122232425262728293031#include <cstdio>#include <cstring>#include <iostream>#include <vector>#include <string>#include <algorithm>using namespace std;typedef long long Int64;typedef unsigned long long UInt64;#define INT64MAX 9223372036854775807#define INT32MAX 2147483647inline int ReadNum(){int x = 0; char ch = getchar(); bool positive = true;for (; !isdigit(ch); ch = getchar()) if (ch == '-') positive = false;for (; isdigit(ch); ch = getchar()) x = x * 10 + ch - '0';return positive ? x : -x;}int main(){int N = ReadNum();int ans = 0;for (int i = 0; i < N; i++){int c = ReadNum();ans ^= c;}