I Wanna Become A 24-Point Master

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

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
            }

        }
    }
}

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