技術標籤：⭐C/C++程式設計筆記c++

#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <ctime>
using namespace std;
 
int in[5];
 
int calc(int operName, int x, int y)
{
    if (operName == 1)//+ 
    {
        return x + y;
    }
 
    if (operName == 2)//-
    {
        if
 
 (x - y <= 0)
        {
            return -3456731;
        }
 
        return x - y;
    }
 
    if (operName == 3)//*
    {
        if (x*y <= 0)
        {
            return -464652;
        }
 
        return x * y;
    }
 
    if (operName == 4)// /
    {
        if (x*y == 0 || x < y || x % y !=
 
 0)
        {
            return -5643212;
        }
 
        return x / y;
    }
}
 
char oper[] = { '!','+','-','*','/' };
 
int random()
{
    return rand() % 12 + 1;
}
 
int main()
{
    srand(time(NULL));
 
    cout << "Initial numbers are: ";
    for (int i = 1; i <= 4; i++)
    {
 

        in[i] = random();
        cout << in[i] << " ";
    }
    cout << endl;
 
    sort(in + 1, in + 5);
 
    do
    {
        for (int i = 1; i <= 4; i++)//3pos,fill operator 
        {
            for (int j = 1; j <= 4; j++)
            {
                for (int k = 1; k <= 4; k++)
                {
                    int s1 = calc(i, in[1], in[2]);
                    int s2 = calc(j, s1, in[3]);
                    int s3 = calc(k, s2, in[4]);
                    if (s3 == 24)
                    {
                        if (in[1] >= in[2] && s1 >= in[3] && s2 >= in[4])
                        {
                            cout << in[1] << oper[i] << in[2] << '=' << s1 << endl;
                            cout << s1 << oper[j] << in[3] << '=' << s2 << endl;
                            cout << s2 << oper[k] << in[4] << '=' << s3 << endl;
                            return 0;
                        }
                    }
 
 
                    s1 = calc(j, in[2], in[3]);
                    s2 = calc(i, in[1], s1);
                    s3 = calc(k, s2, in[4]);
                    if (s3 == 24)
                    {
                        if (in[2] >= in[3] && in[1] >= s1 && s2 >= in[4])
                        {
                            cout << in[2] << oper[j] << in[3] << '=' << s1 << endl;
                            cout << in[1] << oper[i] << s1 << '=' << s2 << endl;
                            cout << s2 << oper[k] << in[4] << '=' << s3 << endl;
                            return 0;
                        }
                    }
 
 
                    s1 = calc(j, in[2], in[3]);
                    s2 = calc(k, s1, in[4]);
                    s3 = calc(i, in[1], s2);
                    if (s3 == 24)
                    {
                        if (in[2] >= in[3] && s1 >= in[4] && in[1] >= s2)
                        {
                            cout << in[2] << oper[j] << in[3] << '=' << s1 << endl;
                            cout << s1 << oper[k] << in[4] << '=' << s2 << endl;
                            cout << in[1] << oper[i] << s2 << '=' << s3 << endl;
                            return 0;
                        }
                    }
 
 
                    s1 = calc(i, in[1], in[2]);
                    s2 = calc(k, in[3], in[4]);
                    s3 = calc(j, s1, s2);
                    if (s3 == 24)
                    {
                        if (in[1] >= in[2] && in[3] >= in[4] && s1 >= s2)
                        {
                            cout << in[1] << oper[i] << in[2] << '=' << s1 << endl;
                            cout << in[3] << oper[k] << in[4] << '=' << s2 << endl;
                            cout << s1 << oper[j] << s2 << '=' << s3 << endl;
                            return 0;
                        }
                    }
 
 
                    s1 = calc(k, in[3], in[4]);
                    s2 = calc(j, in[2], s1);
                    s3 = calc(i, in[1], s2);
                    if (s3 == 24)
                    {
                        if (in[3] >= in[4] && in[2] >= s1 && in[1] >= s2)
                        {
                            cout << in[3] << oper[k] << in[4] << '=' << s1 << endl;
                            cout << in[2] << oper[j] << s1 << '=' << s2 << endl;
                            cout << in[1] << oper[i] << s2 << '=' << s3 << endl;
                            return 0;
                        }
                    }
                }
            }
        }
    } while (next_permutation(in + 1, in + 5));
 
    cout << "No answer!" << endl;
    return 0;
}