寻找奇数

时间最优

#include<stdio.h>

inline int read(){
    int x=0;char c=getchar();
    while (c<'0'||c>'9') c=getchar();
    while (c>='0'&&c<='9') x=x*10+c-'0',c=getchar();
    return x;
}

int main() {
    int res , n ;
    n = read();
    for (int i = 1 ; i <= n ; i ++) {
        res ^= read();
    }
    printf("%d\n",res);
}