Codeforces Round #644 (Div. 3) 题解

题目链接：https://codeforces.com/contest/1360

 	/*
 	 A题
 	 creat by dzz
 	*/
    #include <bits/stdc++.h>
    using namespace std;
    int main () {
    	int T;
    	cin >> T;
    	while(T--) {
    		int a, b;
    		cin >> a >> b;
    		if(a > b) {
    			swap(a, b);
    		}
    		// int c = 2 * a * b;
    		if(a * a >= 2 * a * b || b * b >= 2 * a * b) {
    			cout << (a * a >= 2 * a * b ? a * a : b * b) << endl;
    			continue;
    		}
    		cout << (4 * a * a >= 2 * a * b ? 4 * a * a : 4 * b * b) << endl;
    	}
    }

 	/*
 	 B题
 	 creat by dzz
 	*/
    #include <bits/stdc++.h>
    using namespace std;
    int main () {
    	int T;
    	cin >> T;
    	while(T--) {
    		int n;
    		cin >> n;
    		std::vector<int> v;
    		while(n--)	{
    			int temp;
    			cin >> temp;
    			v.push_back(temp);
    		}
    		sort(v.begin(), v.end());
    		int ans = 0x3f3f3f3f;
    		for(int i = 1; i < v.size(); ++i) {
    			ans = min(ans, v[i] - v[i - 1]);
    		}
    		cout << ans << endl;
    	}
    }

 	/*
 	 C题
 	 creat by dzz
 	*/
    #include <bits/stdc++.h>
    using namespace std;
    int main () {
    	int T;
    	cin >> T;
    	while(T--) {
    		int n;
    		cin >> n;
    		std::vector<int> v;
    		int oddnum = 0;
    		for(int i = 0; i < n; ++i){
    			int temp;
    			cin >> temp;
    			if(temp & 1) {
    				oddnum++;
    			}
    			v.push_back(temp);
    		}
    		int oddeven = n - oddnum;
    		if(!(oddnum & 1)) {
    			cout << "YES" << endl;
    		}
    		else {
    			bool ok = 0;
    			sort(v.begin(), v.end());
    			for(int i = 1; i < v.size(); ++i) {
    				if(v[i] - v[i - 1] == 1) {
    					ok = 1;
    					break;
    				}
    			}
    			if(ok) {
    				cout << "YES" << endl;
    			}
    			else {
    				cout << "NO" << endl;
    			}
    		}
    	}
    }

 	/*
 	 D题
 	 creat by dzz
 	*/
    #include <bits/stdc++.h>
    using namespace std;
    typedef long long ll;
    int main()
    {
    	int n, p;
    	int t;
    	cin >> t;
    	while(t--){
    		cin >> n >> p;
    		int ans = 0;
    		for(int i = 1; i * i <= n && i <= p; i++) {
    			if(n % i == 0){
    				ans = max(ans, i);
    				if(n / i <= p)
    					ans = max(ans, n / i);
    			}	
    		}
    		ans = n / ans;
    		cout << ans<< endl;
    	}
    	return 0;
    }

 	/*
 	 E题
 	 creat by dzz
 	*/
    #include <bits/stdc++.h>
    using namespace std;
    typedef long long ll;
    char a[100][100];
    int main()
    {
    	ll t;
    	cin >> t;
    	ll n;
    	while(t--){
    		int n;
    		cin >> n;
    		for(int i = 0; i < n; ++i) {
    			cin >> a[i];
    		}
    		bool flag = 1;
    		for(int i = 0; i < n - 1; ++i) {
    			for(int j = 0; j < n - 1; ++j) {
    				if(a[i][j] == '1' && a[i + 1][j] == '0' && a[i][j + 1] == '0') {
    					flag = 0;
    					break;
    				}
    				if(!flag) {
    					break;
    				}
    			}
    		}
    		if(flag) {
    			cout << "YES" << endl;
    		}
    		else {
    			cout << "NO" << endl;
    		}
    	}
    	return 0;
    }

 	/*
 	 F题
 	 creat by dzz
 	*/
    #include <bits/stdc++.h>
    using namespace std;
    typedef long long ll;  
    int main()
    {
    	ios::sync_with_stdio(false);
    	cin.tie(0);
    	ll t;
    	cin >> t;
    	while(t--){
    		string s[15];
    		int n, m;
    		cin >> n >> m;
    		for(int i = 0; i < n; ++i) {
    			cin >> s[i];
    		}
    		string ans = "-1";
    		function<bool(string)> check = [&](string t) {
    			for(int i = 0; i < n; ++i) {
    				int cnt = 0;
    				for(int j = 0; j < m; ++j) {
    					cnt += (s[i][j] != t[j]);	//不等cnt++
    				}
    				if(cnt > 1) {
    					return false;
    				}
    			}
    			return true;
    		};
    		for(int i = 0; i < n; ++i) {
    			for(int j = 0; j < m; ++j) {
    				for(int k = 0; k < 26; ++k) {
    					string ss = s[i];
    					ss[j] = 'a' + k;
    					if(check(ss)) {
    						ans = ss;
    					}
    				}
    			}
    		}
    		cout << ans << endl;
    	}
    	return 0;
    }