#include <cstdio>
#define MAX	200005

int n, k, p;
int a[MAX], b[MAX];

int jumpList[MAX];	// jumpList[i] is the index
// of the next right color behind i

inline void readData() {
	scanf("%d%d%d", &n, &k, &p);
	for (int i = 0; i < n; i++) {
		scanf("%d%d", &(a[i]), &(b[i]));
	}
}

inline void pre1(int *color, int n) {
	for (int i = 0; i < n; i++) {
		for (int j = i + 1; j < n; j++) {
			if (a[i] == a[j]) {
				jumpList[i] = j;
				break;
			}
		}
		//printf("%d ", jumpList[i]);
	}
}

int main() {
	//freopen("in.txt", "r", stdin);
	readData();
	pre1(a, n);

	unsigned long long int cnt = 0;
	for (int i = 0; i < n - 1; i++) {
		int left = i;
		int right = jumpList[left];
		while (right != 0) {
			for (int i = left; i <= right; i++) {
				//printf("check %d\n", i);
				if (b[i] <= p) {
					cnt++;
					break;
				}
			}
			right = jumpList[right];
		}
	}
	printf("%lld\n", cnt);

	return 0;
}

这个算法的本质是对暴力的优化

各位看看能不能再优化一点点的，如果能的话欢迎提出来，如果不行就算了 先向我的马蜂谢罪