Educational Codeforces Round 63 (Rated for Div. 2) (A,B,C)

拼搏现实的明天。 2022-02-15 02:30 252阅读 0赞

这次比赛很顺利的出了3个题，rating上涨了98，菜菜的我后面的不会了。

[A - Reverse a Substring][]

#include<bits/stdc++.h>
    using namespace std;
    typedef long long ll;
    const int maxn=1e5+10;
    const int MOD=1e9+7;
    
    
    int main(){
    	int n;
    	scanf("%d\n",&n);
    	string t;
    	cin>>t;
    	int l=0,r=0;
    	for(int i=1;i<n;i++){
    		if(t[i]<t[l]){
    			r=i;
    			break;
    		}else l=i;
    	}
    	if(r!=0){
    		printf("YES\n");
    		printf("%d %d\n",l+1,r+1);
    	}else{
    		printf("NO\n");
    	}
    	
    	return 0;
    }

[B - Game with Telephone Numbers][]

#include<bits/stdc++.h>
    using namespace std;
    typedef long long ll;
    const int maxn=1e5+10;
    const int MOD=1e9+7;
    
    
    int main(){
    	int n,cnt=0;
    	scanf("%d\n",&n);
    	string t;
    	cin>>t;
    	
    	n=n-10;
    	for(int i=0;i<n;i++){
    		if(t[i]=='8') cnt++;
    	}
    	
    	if(cnt>=(n+1)/2){
    		printf("YES\n");
    	}else{
    		printf("NO\n");
    	}
    	
    	return 0;
    }

[C - Alarm Clocks Everywhere][]

#include<bits/stdc++.h>
    using namespace std;
    typedef long long ll;
    const int maxn=1e5+10;
    const int MOD=1e9+7;
    
    ll gcd(ll a,ll b){
    	if(b==0) return a;
    	return gcd(b,a%b);
    }
    
    
    int main(){
    	ll n,m;
    	scanf("%lld%lld",&n,&m);
    	ll x,p,a1,b1=-1,g,pre,b;
    	scanf("%lld%lld",&a1,&b);
    	g=b-a1;
    	pre=b;
    	for(ll i=3;i<=n;i++){
    		scanf("%lld",&x);
    		g=gcd(g,x-pre);
    		pre=x;
    	}
    	for(ll i=1;i<=m;i++){
    		scanf("%lld",&p);
    		if(g%p==0) b1=i;
    	}
    	if(b1!=-1){
    		printf("YES\n%lld %lld\n",a1,b1);
    	}else{
    		printf("NO\n");
    	}
    	return 0;
    }

[A - Reverse a Substring]: https://codeforces.com/contest/1155/problem/A
[B - Game with Telephone Numbers]: https://codeforces.com/contest/1155/problem/B
[C - Alarm Clocks Everywhere]: https://codeforces.com/contest/1155/problem/C