pt

a.cpp

#include <iostream>
#include <map>
#include <vector>
#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <string>

using namespace std;


typedef long long LL;
int main(){
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
	string s, t;
	cin >> s >> t;
	int j = 0, sum = 0;
	for(int i = 0; i < s.length(); i++){
		for(j; j < t.length(); j++)
			if(s[i] == t[j]){
				j++;
				sum++;
				break;
			}
	}
	if(sum != s.length()) cout << "NO";
	else cout << "YES";
	return 0;
}

b.cpp

#include <iostream>
#include <map>
#include <vector>
#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <string>

using namespace std;

const int simples[168] = {2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,101,103,107,109,113,127,131,137,139,149,151,157,163,167,173,179,181,191,193,197,199,211,223,227,229,233,239,241,251,257,263,269,271,277,281,283,293,307,311,313,317,331,337,347,349,353,359,367,373,379,383,389,397,401,409,419,421,431,433,439,443,449,457,461,463,467,479,487,491,499,503,509,521,523,541,547,557,563,569,571,577,587,593,599,601,607,613,617,619,631,641,643,647,653,659,661,673,677,683,691,701,709,719,727,733,739,743,751,757,761,769,773,787,797,809,811,821,823,827,829,839,853,857,859,863,877,881,883,887,907,911,919,929,937,941,947,953,967,971,977,983,991,997};
typedef long long LL;
int main(){
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
	LL n, m = 1;
	cin >> n;
	for(int i = 0; i < 168; i++){
		LL a = 1;
		while(n % simples[i] == 0){
			n /= simples[i];
			a++;
		}
		m *= a;
	}
	cout << m;
	return 0;
}

c.cpp

#include <iostream>
#include <map>
#include <vector>
#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <string>

using namespace std;


typedef long long LL;
int main(){
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
	long long h, w, res = 0;
	cin  >> h >> w;
	cout << w * (w+1) * h * (h+1) / 4;
	return 0;
}

d.cpp

#include <iostream>
#include <map>
#include <vector>
#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <string>

using namespace std;


typedef long long LL;
int main(){
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
	int n, m, k, r;
	cin >> n >> m >> k;
	r = n * m;
	if(r % k){
		cout << -1;
		return 0;
	}
	int i = 0;
	for(int j = 0; j < n; j++){

		for(int o = 0; o < m; o++){
			cout << i / k + 1 << " ";
			i++;
		}
		cout << endl;
		
		j++;
		if(j >= n) break;
		
		for(int o = m-1; o >= 0; o--){
			cout << i / k + 1 << " ";
			i++;
		}
		cout << endl;
	}
	return 0;
}