HDU 6045 Is Derek lying?【思维】

题目来戳呀

Problem Description

Derek and Alfia are good friends.Derek is Chinese,and Alfia is Austrian.This summer holiday,they both participate in the summer camp of Borussia Dortmund.During the summer camp,there will be fan tests at intervals.The test consists of N choice questions and each question is followed by three choices marked “A” “B” and “C”.Each question has only one correct answer and each question is worth 1 point.It means that if your answer for this question is right,you can get 1 point.The total score of a person is the sum of marks for all questions.When the test is over,the computer will tell Derek the total score of him and Alfia.Then Alfia will ask Derek the total score of her and he will tell her: “My total score is X,your total score is Y.”But Derek is naughty,sometimes he may lie to her. Here give you the answer that Derek and Alfia made,you should judge whether Derek is lying.If there exists a set of standard answer satisfy the total score that Derek said,you can consider he is not lying,otherwise he is lying.

Input

The first line consists of an integer T,represents the number of test cases.

For each test case,there will be three lines.

The first line consists of three integers N,X,Y,the meaning is mentioned above.

The second line consists of N characters,each character is “A” “B” or “C”,which represents the answer of Derek for each question.

The third line consists of N characters,the same form as the second line,which represents the answer of Alfia for each question.

Data Range:1≤N≤80000,0≤X,Y≤N,∑Ti=1N≤300000

Output

For each test case,the output will be only a line.

Please print “Lying” if you can make sure that Derek is lying,otherwise please print “Not lying”.

Sample Input

2
3 1 3
AAA
ABC
5 5 0
ABCBC
ACBCB

Sample Output

Not lying
Lying

题意：

有n道题，每道题有3个选项，我和你做，我得X分，你得Y分，但我可能骗你，根据两个人的答案来判断我有没有骗你。

想法：

分数=相同答案的得分数+不同答案的得分数
首先，两个人的得分之差一定<=不同的答案数，即abs(y-x)<=(n-same)
其次，来讨论两个人得分之和 x+y<=n+same
证法1：
得分之和max时，就是两个人相同答案都是对的，并且一定有人在不同答案里得分（无非就是我对你错你对我错，不同答案的分数两人分了 ），不能让两个人都错（都错会使分数流失），所以(x+y)max=same+same+n-same=n+same。
证法2：
可以由你的得分来推测我的。
我得分最大值=相同答案的全对+我在不同答案得分数=相同答案的全对+不同答案总得分数-你在不同答案的得分数，所以(x)max=same+n-same-(y-same)=n-y+same

同时满足两个条件则我没有在骗你~

#include<cstdio>#include<cstring>#include<algorithm>using namespace std;char a[80004],b[80004];int main(){    int t,n,x,y;    scanf("%d",&t);    while(t--)    {        int cnt=0;        scanf("%d %d %d",&n,&x,&y);        scanf("%s",a);        scanf("%s",b);        for(int i=0; i<n; ++i)        {            if(a[i]==b[i])                cnt++;        }        if(x<=(n-y+cnt)&&abs(y-x)<=(n-cnt))            printf("Not lying\n");        else            printf("Lying\n");    }    return 0;}

ps:想通了就是很简单的思维题啊QAQ 不知道我讲的清不清楚~