[ACM_水题] ZOJ 3706 [Break Standard Weight 砝码拆分，可称质量种类，暴力]

 

 

The balance was the first mass measuring instrument invented. In its traditional form, it consists of a pivoted horizontal lever of equal length arms, called the beam, with a weighing pan, also called scale, suspended from each arm (which is the origin of the originally plural term "scales" for a weighing instrument). The unknown mass is placed in one pan, and standard masses are added to this or the other pan until the beam is as close to equilibrium as possible. The standard weights used with balances are usually labeled in mass units, which are positive integers.

With some standard weights, we can measure several special masses object exactly, whose weight are also positive integers in mass units. For example, with two standard weights 1 and 5, we can measure the object with mass 1, 4, 5 or 6 exactly.

In the beginning of this problem, there are 2 standard weights, which masses are x and y. You have to choose a standard weight to break it into 2 parts, whose weights are also positive integers in mass units. We assume that there is no mass lost. For example, the origin standard weights are 4 and 9, if you break the second one into 4and 5, you could measure 7 special masses, which are 1, 3, 4, 5, 8, 9, 13. While if you break the first one into 1 and 3, you could measure 13 special masses, which are 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13! Your task is to find out the maximum number of possible special masses.

Input

There are multiple test cases. The first line of input is an integer T < 500 indicating the number of test cases. Each test case contains 2 integers x and y. 2 ≤ x, y ≤ 100

Output

For each test case, output the maximum number of possible special masses.

Sample Input

2

4 9

10 10

Sample Output

13

9

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Author: YU, Zhi
Contest: The 10th Zhejiang Provincial Collegiate Programming Contest

 

题目大意：给你2个砝码X,Y,你可以把一个打破变成2个砝码，用新的3个砝码可以称出最多质量的种类是多少？

解题思路：暴力枚举所有的打破砝码的方法，然后针对每种情况计算出所有可能的组合放进map里[可以去除重复的数字],则map的大小就是该种拆法可以称出的种类数。[这里要注意0不算]

 

 1 #include<iostream>

 2 #include<algorithm>

 3 #include<set>

 4 using namespace std;

 5 int main(){

 6     int T;

 7     cin>>T;

 8     while(T--){

 9         int x,y;

10         cin>>x>>y;

11         set<int>Q;

12         Q.clear();

13         int max=1;

14         for(int i=1;i<=x/2;i++){

15             int a=i,b=x-i,c=y;

16             Q.insert(a);//单独一个砝码

17             Q.insert(b);

18             Q.insert(c);

19             Q.insert(a+b);//2个砝码

20             if(a-b!=0)Q.insert(abs(a-b));

21             Q.insert(a+c);

22             if(a-c!=0)Q.insert(abs(a-c));

23             Q.insert(b+c);

24             if(b-c!=0)Q.insert(abs(b-c));

25             Q.insert(a+b+c);//3个砝码

26             if(a+b-c!=0)Q.insert(abs(a+b-c));

27             if(a-b+c!=0)Q.insert(abs(a-b+c));

28             if(a-b-c!=0)Q.insert(abs(a-b-c));

29             //cout<<a<<' '<<b<<' '<<c<<' '<<Q.size()<<'\n';

30             if(Q.size()>max)max=Q.size();

31             Q.clear();

32         }//拆x

33         for(int i=1;i<=y/2;i++){

34             int a=i,b=y-i,c=x;

35             Q.insert(a);

36             Q.insert(b);

37             Q.insert(c);

38             Q.insert(a+b);

39             if(a-b!=0)Q.insert(abs(a-b));

40             Q.insert(a+c);

41             if(a-c!=0)Q.insert(abs(a-c));

42             Q.insert(b+c);

43             if(b-c!=0)Q.insert(abs(b-c));

44             Q.insert(a+b+c);

45             if(a+b-c!=0)Q.insert(abs(a+b-c));

46             if(a-b+c!=0)Q.insert(abs(a-b+c));

47             if(a-b-c!=0)Q.insert(abs(a-b-c));

48             //cout<<a<<' '<<b<<' '<<c<<' '<<Q.size()<<'\n';

49             if(Q.size()>max)max=Q.size();

50             Q.clear();

51         }//拆y

52         cout<<max<<'\n';

53     }return 0;

54 

55 }