【PAT甲级】1041. Be Unique (20)

#include <stdio.h>

int main(int argc, char *argv[]) {
int n;
scanf("%d", &n);
int i, j, k;
int cnt[100001] = {0};
int *a = new int
;
for (i = 0; i < n; i++) {
scanf("%d", &a[i]);
cnt[a[i]]++;
}
for (i = 0; i < n; i++) {
if (cnt[a[i]] == 1) {
printf("%d\n", a[i]);
return 0;
}
}
printf("None\n");
return 0;
}