#include "Cal.h"
void    DelSpace(char* str)
{
    char* curr = str;
    while (*curr=*str++)
        if (*curr!=' ') curr++;
}
void    GetExpression(int a[], int n)
{
    static char token[] = {'+','-',' '};
    static char buff[256];
    static CAL    cal;

    sprintf(buff, "1%c2%c3%c4%c5%c6%c7%c8%c9",
        token[a[0]], token[a[1]], token[a[2]], token[a[3]],
        token[a[4]], token[a[5]],token[a[6]], token[a[7]]);
    DelSpace(buff);
//    cout << buff << endl;
    int    result = cal.Evalue(buff);
    if (cal.GetError() == "OK" && result == 100)
            cout << buff << '=' << result << endl;
}
void    DoEnum(int n, int curr, int to[])
{
    if (curr == n)
    {
        GetExpression(to, n);
    }
    else
    {
        for (int i = 0; i < 3; ++i)
        {
            to[curr] = i;
            DoEnum(n, curr+1, to);
        }
    }
}
int main()
{
    int to[8];
    DoEnum(8, 0, to);
    return 0;
}
1+2+3-4+5+6+78+9=100
1+2+34-5+67-8+9=100
1+23-4+5+6+78-9=100
1+23-4+56+7+8+9=100
12+3+4+5-6-7+89=100
12+3-4+5+67+8+9=100
12-3-4+5-6+7+89=100
123+4-5+67-89=100
123+45-67+8-9=100
123-4-5-6-7+8-9=100
123-45-67+89=100
Press any key to continue

//重新写的一个简单的CAL
#include <iostream>
using namespace std;
class CAL
{
    enum{NUMBER, OPERATOR, END, UNKNOWN};
    class Token
    {
    public:
        int    value;
        int    type;
    };
    const char*    buff;
    int        curr;
    Token    tk;
public:

    int        Evalue(const char* exp)
    {
        int value = 0;
        int    sign = 1;
        buff = exp;
        curr = 0;
        do{
            MoveToNextToken();
            switch (tk.type)
            {
            case    NUMBER: value += sign * tk.value;break;
            case    OPERATOR: sign = tk.value == '+' ? 1 : -1;
            }
        }while (tk.type==NUMBER||tk.type==OPERATOR);
        return value;
    }
    void    MoveToNextToken()
    {
        static char temp[256];
        tk.type = UNKNOWN, tk.value = 0;

        if (!buff[curr]) 
        {
            tk.type = END;
            return;
        }
        if (buff[curr]>='0'&&buff[curr]<='9')
        {
            int value = 0;
            while (buff[curr]&&buff[curr]>='0'&&buff[curr]<='9')
                value = value * 10 + buff[curr++] - '0';
            tk.value = value;
            tk.type = NUMBER;
            return;
        }
        switch (buff[curr++])
        {
        case '+':
            tk.type = OPERATOR, tk.value = '+';return;
        case '-':
            tk.type = OPERATOR, tk.value = '-';return;
        }
        
        tk.type = UNKNOWN;
        return;
    }
};
void    DelSpace(char* str)
{
    char* curr = str;
    while (*curr=*str++)
        if (*curr!=' ') curr++;
}
void    GetExpression(int a[], int n)
{
    static char token[] = {'+','-',' '};
    static char buff[256];
    static CAL    cal;
    
    sprintf(buff, "1%c2%c3%c4%c5%c6%c7%c8%c9",
        token[a[0]], token[a[1]], token[a[2]], token[a[3]],
        token[a[4]], token[a[5]],token[a[6]], token[a[7]]);
    DelSpace(buff);
    //    cout << buff << endl;
    int    result = cal.Evalue(buff);
    if (result == 100)
        cout << buff << '=' << result << endl;
}
void    DoEnum(int n, int curr, int to[])
{
    if (curr == n)
    {
        GetExpression(to, n);
    }
    else
    {
        for (int i = 0; i < 3; ++i)
        {
            to[curr] = i;
            DoEnum(n, curr+1, to);
        }
    }
}
int main()
{
    int to[8];
    DoEnum(8, 0, to);
    return 0;
}

 sprintf(buff, "1%c2%c3%c4%c5%c6%c7%c8%c9",
        token[a[0]], token[a[1]], token[a[2]], token[a[3]],
        token[a[4]], token[a[5]],token[a[6]], token[a[7]]);