Codeforces Round #553 (Div. 2)

本是古典何须时尚 2022-02-17 10:14 103阅读 0赞

### A. Maxim and Biology ###

题目：[http://codeforces.com/contest/1151/problem/A][http_codeforces.com_contest_1151_problem_A]

###   暴力 ###

### B. Dima and a Bad XOR ###

题目：[http://codeforces.com/contest/1151/problem/B][http_codeforces.com_contest_1151_problem_B]

所选数异或不等于零即可 按题意模拟

理解错题意 gg

#include<iostream>
    #define N 1010
    using namespace std;
    int n,m;
    int a[N][N],c[N];
    void pr(){
    	cout<<"TAK"<<endl;
    	for(int i=1;i<=n;i++)
    	cout<<c[i]<<" ";
    	 
    }
    int main(){
    	cin>>n>>m;
    	for(int i=1;i<=n;i++){
    		for(int j=1;j<=m;j++){
    			cin>>a[i][j];
    		}
    	}
    	int sum=0;
    	for(int i=1;i<=n;i++){
    		sum^=a[i][1];
    		c[i]=1;
    	}
    	if(sum) pr();
    	else{
          for(int i=1;i<=n;i++){
    		for(int j=2;j<=m;j++){
    			if(a[i][j]!=a[i][1]){
    				c[i]=j;
    				pr();
    				return 0;
    			}
    		}
    	  }
    	  cout<<"NIE"<<endl;
         }
    	return 0;
    }

### C. Problem for Nazar ###

题目：[http://codeforces.com/contest/1151/problem/C][http_codeforces.com_contest_1151_problem_C]

a\[\]=\{1,3,5,7,9,11,...2n-1\};

b\[\]=\{2,4,6,8,10,12,14,...2n\};

将a\[\],b\[\],以1，2，4，8，..的个数合并

1 / 2 4 / 3 5 7 9 / 6 8 10  12 14 16 18 20 / 11..

找区间l,r的和

解：找出n位置前出现的a\[\]的个数 b\[\]的个数  等差数列求和

#include<iostream>
    #define ll long long
    using namespace std;
    const ll M = 1000000007;
    ll slove(ll  up){
        ll x=0,f=0,nx=1,a=0,b=0;
        while(x<up){
        	if(!f) a+=min(up-x,nx);
        	else b+=min(up-x,nx);
        	f=1-f;
        	x+=nx;
        	nx*=2;
    	}
    	a%=M;b%=M;
    	return  (a*a)%M+((1+b)*b)%M;
    }
    int main(){
    	ll l,r;
    	cin>>l>>r;
    	cout<<((slove(r)-slove(l-1))%M+M)%M<<endl;
    	return 0;
    }

### D. Stas and the Queue at the Buffet ###

题目：[http://codeforces.com/contest/1151/problem/D][http_codeforces.com_contest_1151_problem_D]

考虑左右数对乘积影响的权值     按照a-b的结果从大到小排序

#include<iostream>
    #include<algorithm>
    #define ll long long
    #define N 100010
    #define P pair<ll,ll>
    using namespace std;
    int n;
    P a[N],b[N];
    bool cmp1(P x,P y){
    	return x.first-x.second>y.first-y.second;
    }
    
    int main(){
    	cin>>n;
    	for(int i=1;i<=n;i++){
    		ll x,y;
    		cin>>x>>y;
    		a[i]=P(x,y);
    		b[i]=a[i];
    	}
    	sort(a+1,a+1+n,cmp1);
    	ll sum1=0;
    	for(int i=1;i<=n;i++){
    		sum1+=a[i].first*(i-1)+a[i].second*(n-i);
    	}
    	cout<<sum1<<endl;
    	return 0;
    }

### E. Number of Components ###

题目：[http://codeforces.com/contest/1151/problem/E][http_codeforces.com_contest_1151_problem_E]

还是看不懂：[https://blog.csdn.net/qq\_41829060/article/details/89397907][https_blog.csdn.net_qq_41829060_article_details_89397907]

[http_codeforces.com_contest_1151_problem_A]: http://codeforces.com/contest/1151/problem/A
[http_codeforces.com_contest_1151_problem_B]: http://codeforces.com/contest/1151/problem/B
[http_codeforces.com_contest_1151_problem_C]: http://codeforces.com/contest/1151/problem/C
[http_codeforces.com_contest_1151_problem_D]: http://codeforces.com/contest/1151/problem/D
[http_codeforces.com_contest_1151_problem_E]: http://codeforces.com/contest/1151/problem/E
[https_blog.csdn.net_qq_41829060_article_details_89397907]: https://blog.csdn.net/qq_41829060/article/details/89397907