02-線性結構4 Pop Sequence (25分)

Sample Input:
5 7 5
1 2 3 4 5 6 7
3 2 1 7 5 6 4
7 6 5 4 3 2 1
5 6 4 3 7 2 1
1 7 6 5 4 3 2

Sample Output:
YES
NO
NO
YES
NO

#include <iostream>
#include <vector>
using namespace std;
bool judge(vector<int> v, int m);
int main(void) {
	int m, n, k;
	scanf("%d%d%d", &m, &n, &k);
	while (k--) {
		int i = 0;
		vector<int> v(n);
		while (i < n) 
			scanf("%d", &v[i++]);
		if (judge(v, m)) printf("YES\n");
		else printf("NO\n");
		v.clear();
	}
	return 0;
}

bool judge(vector<int> v, int m) {
	int t = v[0], t1 = v[0], n = v.size();
	for (size_t i = 0; i != n; ++i) {		
		if (v[i] >= t) {
			t = v[i];
			if (t - i > m) return false;
			t1 = v[i];
		}
		else{
			if(v[i] <= t1) t1 = v[i];
			else return false;
		}	
	}
	return true;
}  

//也可以用堆棧直接模擬
#include <stack>
#include <iostream>
using namespace std;
int main() {
	int m, n, k;
	scanf("%d%d%d", &m, &n, &k);
	while (k--) {
		bool flag = true;
		stack<int> s;
		int nt = n;
		int j = 1;
		while (nt--) {
			int num;
			scanf("%d", &num);
			if (flag) {
				while (s.empty() || s.top() != num) {
					s.push(j++);
					if (s.size() > m) { flag = false;break; }
				}
				if (flag && s.size() >= 1 && s.top() == num)
					s.pop();
			}
		}
		if (flag) printf("YES\n");
		else printf("NO\n");
		printf("---\n");
	}
	return 0;
}