HDU 5308 I Wanna Become A 24-Point Master（2015多校第二场）

I Wanna Become A 24-Point Master

Time Limit: 2000/1000 MS (Java/Others)    Memory
Limit: 65536/65536 K (Java/Others)

Total Submission(s): 485    Accepted Submission(s): 191
Special Judge

Problem Description

Recently Rikka falls in love with an old but interesting game -- 24 points. She wants to become a master of this game, so she asks Yuta to give her some problems to practice.

Quickly, Rikka solved almost all of the problems but the remained one is really difficult:

In this problem, you need to write a program which can get 24 points with 

 numbers,
which are all equal to 

.

 

Input

There are no more then 100 testcases and there are no more then 5 testcases with 









.
Each testcase contains only one integer 






















 

Output

For each testcase:

If there is not any way to get 24 points, print a single line with -1.

Otherwise, let 

 be
an array with 







 numbers
and at firsrt 























.
You need to print 





 lines
and the 

th
line contains one integer 

,
one char 

 and
then one integer c, where 

















 and 

 is
"+","-","*" or "/". This line means that you let 



 and 



 do
the operation 

 and
store the answer into 







.

If your answer satisfies the following rule, we think your answer is right:

1. 
















2. Each position of the array 

 is
used at most one tine.

3. The absolute value of the numerator and denominator of each element in array 

 is
no more than 






 

Sample Input

4

 

Sample Output

1 * 2
5 + 3
6 + 4

 

Source

2015 Multi-University Training Contest 2

#include <iostream>
#include <cstring>
#include <cstdlib>
#include <cstdio>
#include <algorithm>
using namespace std;
int N;
int main()
{
while(scanf("%d", &N)!=EOF)
{
if(N == 1 || N == 2 || N == 3 ) printf("-1\n");
else if(N == 4)
{
printf("1 * 2\n");
printf("5 + 3\n");
printf("6 + 4\n");
}
else if(N == 5)
{
printf("1 * 2\n");//6  25
printf("3 * 6\n");//7  125
printf("7 - 4\n");//8  120
printf("8 / 5\n");//9  24
}
else if(N == 6)
{
printf("1 * 2\n");//7  36
printf("7 - 3\n");//8  30
printf("8 - 4\n");//9  24
printf("9 + 5\n");//10 30
printf("10 - 6\n");//11 24
}
else if(N == 7)
{
printf("1 / 2\n");//8  1
printf("3 + 8\n");//9 8
printf("4 + 5\n");//10 14
printf("10 + 6\n");//11 21
printf("11 / 7\n");//12 3
printf("12 * 9\n");//13 24
}
else if(N == 8)
{
printf("1 + 2\n");//9  16
printf("3 + 9\n");//10 24
printf("4 - 5\n");//11 0
printf("11 * 6\n");//12 0
printf("12 * 7\n");//13 0
printf("13 * 8\n");//14 0
printf("14 + 10\n");//15 24
}
else if(N == 9)
{
printf("1 + 2\n");//10   18
printf("10 + 3\n");//11  27
printf("11 * 4\n");//12  243
printf("12 / 5\n");//13  27
printf("6 + 7\n");//14   18
printf("14 + 8\n");//15  27
printf("15 / 9\n");//16  3
printf("13 - 16\n");//17 24
}
else if(N == 10)
{
printf("1 + 2\n");//11   20
printf("3 + 4\n");//12   20
printf("12 + 5\n");//13  30
printf("13 + 6\n");//14  40
printf("14 / 7\n");//15  4
printf("11 + 15\n");//16 24
printf("8 - 9\n");//17   0
printf("17 / 10\n");//18 0
printf("16 + 18\n");//19 24
}
else if(N == 11)
{
printf("1 + 2\n");//12  22
printf("12 / 3\n");//13 2
printf("13 + 4\n");//14 13
printf("14 + 5\n");//15 24
printf("15 + 6\n");//16 35
printf("16 + 7\n");//17 46
printf("17 + 8\n");//18 57
printf("18 - 9\n");//19 46
printf("19 - 10\n");//20 35
printf("20 - 11\n");//21 24
}
else if(N >= 12 && N % 2 == 0)
{
printf("1 + 2\n");//N+1                  2*N
printf("%d + 3\n",N+1);//N+2             3*N
printf("4 + 5\n");//N+3                  2*N
printf("%d + 6\n",N+3);//N+4             3*N
printf("%d + 7\n",N+4);//N+5             4*N
printf("8 + 9\n");//N+6                  2*N
printf("%d / 10\n",N+2);//N+7            3
printf("%d / 11\n",N+5);//N+8            4
printf("%d / 12\n",N+6);//N+9            2
printf("%d * %d\n",N+7,N+8);//N+10       12
printf("%d * %d\n",N+9,N+10);//N+11      24
for(int i=0;i<(N-12)/2;i++)
{
printf("%d + %d\n",N+11+2*i,13+i*2);//N+12+2*i
printf("%d - %d\n",N+12+2*i,14+i*2);//N+13+2*i
}
}
else if(N>=13 && N % 2 == 1)
{
printf("1 + 2\n");//N+1               2*N
printf("%d + 3\n",N+1);//N+2          3*N
printf("4 + 5\n");//N+3               2*N
printf("%d + 6\n",N+3);//N+4          3*N
printf("%d + 7\n",N+4);//N+5          4*N
printf("%d + 8\n",N+5);//N+6          5*N
printf("%d + 9\n",N+6);//N+7          6*N
printf("%d + 10\n",N+7);//N+8         7*N
printf("%d + 11\n",N+8);//N+9         8*N
printf("%d / 12\n",N+2);//N+10        3
printf("%d / 13\n",N+9);//N+11        8
printf("%d * %d\n",N+10,N+11);//N+12  24
for(int i=0;i<(N-13)/2;i++)
{
printf("%d + %d\n",N+12+2*i,14+i*2);//N+13+2*i
printf("%d - %d\n",N+13+2*i,15+i*2);//N+14+2*i
}

}
}
}