[fysiks]

Originally Posted by Sylwester You should check this: http://forums.alliedmods.net/showthr...55#post1612755 It can solve any valid equation and you don't need to put spaces between operators and values. Also in my opinion you should remove required ! (just check if what player said is valid equation) and instead of blocking say you could edit it and add at the end in green color " = <result>".

PHP Code:

#include <amxmodx>
#include <regex>

new Regex:pPattern
new szPattern[] = "[^^0-9\+\-\*\/\s]"

public plugin_init()
{
    register_plugin("Chat Math", "0.1", "Fysiks")
    register_clcmd("say", "cmdSay")
    new errcode, error[32]
    pPattern = regex_compile(szPattern, errcode, error, charsmax(error))
}

public cmdSay(id)
{
    static szArg[63], err
    read_args(szArg, charsmax(szArg))
    remove_quotes(szArg)
    
    if( regex_match_c(szArg, pPattern, err) == 0 )
    {
        format(szArg, charsmax(szArg), "%s = %d", szArg, mathEvaluateEquation(szArg))
        engclient_cmd(id, "say", szArg)
        return PLUGIN_HANDLED
    }
    return PLUGIN_CONTINUE
}

// This algorithm by Sylwester
// http://forums.alliedmods.net/showpost.php?p=1612755&postcount=2
public mathEvaluateEquation(question[])
{
    static stack[6], top, len
    len = strlen(question)
    for(new i; i<len; i++){
        switch(question[i]){
            case '0'..'9': stack[top] = stack[top]*10+question[i]-'0'
            case '+','-','/','*','x':{
                while(top > 0 && (stack[top-1] == '*' || stack[top-1] == 'x' || stack[top-1] == '/' || question[i] == '+' || question[i] == '-')){
                    switch(stack[top-1]){
                        case '+': stack[top-2] += stack[top]
                        case '-': stack[top-2] -= stack[top]
                        case '/': stack[top-2] /= stack[top]
                        case '*','x': stack[top-2] *= stack[top]
                    }
                    top -= 2                    
                }                
                stack[++top] = question[i]            
                stack[++top] = 0                
            }
        }
    }
    while(top>0){
        switch(stack[top-1]){
            case '+': stack[top-2] += stack[top]
            case '-': stack[top-2] -= stack[top]
            case '/': stack[top-2] /= stack[top]
            case '*','x': stack[top-2] *= stack[top]
        }
        top -= 2
    }       
    return stack[top]
} 


It only does integer math though.