CSU1600: Twenty-four point (DFS)

CSU1600: Twenty-four point (DFS)
Description

Given four numbers, can you get twenty-four through the addition, subtraction, multiplication, and division? Each number can be used only once.

 

Input

The input consists of multiple test cases. each test case contains 4 integers A, B, C, D in a single line (1 <= A, B, C, D <= 13 ).

 

Output

For each case, print the "Yes" or "No". If twenty-four point can be get, print "Yes", otherwise, print "No ".

 

Sample Input

2 2 3 91 1 1 1 5 5 5 1

Sample Output

YesNoYes

HINT

 

For the first sample, (2/3 + 2) * 9 = 24.

 

Source
Question: four digits. You can use the four arithmetic operations to see if you can get 24 o'clock.
Idea: for such a small amount of data, you do not need to doubt your life

#include 
 
   #include 
  
    #include 
   
     #include 
    
      #include 
     
       #include
       #include 
       
         #include 
        
          #include 
         
           #include using namespace std; #define ls 2*i #define rs 2*i+1 #define up(i,x,y) for(i=x;i<=y;i++) #define down(i,x,y) for(i=x;i>=y;i--) #define mem(a,x) memset(a,x,sizeof(a)) #define w(a) while(a) #define LL long long const double pi = acos(-1.0); #define Len 200005 #define mod 19999997 const int INF = 0x3f3f3f3f; #define exp 1e-8 double a[5]; bool dfs(double *a,int n) { if(n==1) return fabs(a[0]-24)