贪心算法区间不相交问题

#include
#include
using namespace std;
const int maxn = 110;
struct Inteval{
	int left, right;
}I[maxn];
bool cmp(Inteval a, Inteval b){
	if (a.left != b.left)
		return a.left > b.left;
	else
		return a.right < b.right;
}
int main(){
	int n;
	while (scanf("%d", &n), n != 0){
		for (int i = 0; i < n; i++){
			scanf("%d %d", &I[i].left, &I[i].right);
		}

		sort(I, I + n, cmp);
		int ans = 1, lastX = I[0].left;
		for (int i = 1; i < n; i++){
			if (I[i].right <= lastX){
				ans++;
				lastX = I[i].left;
			}
		}
		printf("%d", ans);
	}
	getchar();
	return 0;
	
}