ABC370

A

link

判断。

点击查看代码

#include<bits/stdc++.h>

using namespace std;

signed main(){
	
	int l,r;
	cin >> l >> r;
	
	if(l == 1&&r == 0) cout << "Yes";
	else if(l == 0&&r == 1) cout << "No";
	else cout << "Invalid";
	
	return 0;
	
}

B

link

模拟即可。

点击查看代码

#include<bits/stdc++.h>

using namespace std;

int n;
int a[105][105];

signed main(){
	
	cin >> n;
	for(int i = 1;i <= n;++ i){
		for(int j = 1;j <= i;++ j){
			cin >> a[i][j];
		}
	}
	
	int w = 1;
	for(int i = 1;i <= n;++ i){
		if(w >= i) w = a[w][i];
		else w = a[i][w];
	}
	
	cout << w;
	
	return 0;
	
}

C

link

先看哪些位置是变大的，哪些位置是变小的，要想连起来更小，靠前的更小才最优，那么先变小的，从前往后变，再变大的，从后往前变。

点击查看代码

#include<bits/stdc++.h>

using namespace std;

char s[105];
char t[105];
int n,x;
vector<int> ed[5];

signed main(){
	
	cin >> s+1 >> t+1;
	n = strlen(s+1);
	
	for(int i = 1;i <= n;++ i){
		if(t[i] < s[i]) ed[0].push_back(i),x++;
	}
	for(int i = n;i >= 1;-- i){
		if(t[i] > s[i]) ed[1].push_back(i),x++;
	}
	
	cout << x << endl;
	for(int i = 0;i < ed[0].size();++ i){
		int j = ed[0][i];
		s[j] = t[j];
		cout << s+1 << endl;
	}
	for(int i = 0;i < ed[1].size();++ i){
		int j = ed[1][i];
		s[j] = t[j];
		cout << s+1 << endl;
	}
	
	return 0;
	
}