1041. Be Unique (20)

点击打开链接

#include <cstdio>#define MAX 100010int hash[MAX]={0};int a[MAX];int main(){freopen("in.txt","r",stdin);int n;while(scanf("%d",&n)!=EOF){for(int i=0;i<n;i++){scanf("%d",&a[i]);hash[ a[i] ]++;}int flag=0;for(int i=0;i<n;i++){if(hash[a[i]]==1){flag=1;printf("%d\n",a[i]);break;}}if(flag==0){printf("None\n");}}return 0;}