题解 | 小红的三带一

#include<stdio.h>

int three_one(int arr[]) {
	int num1 = 0;
	int num2 = 0;
	for (int i = 0; i < 4; i++) {
		if (arr[0] == arr[i]) {
			num1++;
		}
		if (arr[1] == arr[i]) {
			num2++;
		}
	}
	if (num1 == 3 || num2 == 3) {
		return 1;
	}
	return 0;
}
int main() {
	int n = 0;
	scanf("%d", &n);
	if (n < 4) {
		printf("0");
		return 0;
	}
	int arr[n];
	int times = 0;
	for (int i = 0; i < n; i++) {
		scanf("%d", &arr[i]);
	}
	for (int i = 0; i < n - 3; i++) {
		if (three_one(&arr[i])) {
			times++;
            i +=3;
		}
	}
	printf("%d", times);
	return 0;
}