how i can Solution this ...?

[happyjoker]

hi ..
plezz how i can solution this algorethom

234*+
in Mathematics this solution
2 3*4+
2 12+
2+12
14
thx all

[Bazzy]

Build a postfix parser which has as side-effect the evaluation of the expression

[happyjoker]

thx bro but i need see the program ..

[filipe]

You'll have to write it, then.

[z05DSL3A]

Using a stack
For each item in the postfix expression from the left:
    if the element is a number push it on the stack
    if the element is an operator (+,-,*, or /) then
        pop two numbers off the stack
        make a calculation: the second number popped-operator-first number
        push the result on the stack
When the loop is done the answer is the only item remaining on the stack.

[happyjoker]

thats good bro ...
but : redface:
i m new learning and i start with stack ..
i dont know how i can write this program ..

[Toothkiller]

I feel like all I do lately is link to this site on these forums.

http://www.cplusplus.com/doc/tutorial/

[rocketboy9000]

Ok, look at this code, it's something I already had:

#include "stdio.h"
#include "ctype.h"
int main(){
	int instr;
	int stack[100];
	int sp=0;
	while((instr=getchar())!=EOF){
		if(isdigit(instr)){
			if(sp>=100){
				fputs("stack overflow\n",stderr);
				continue;
			}else stack[sp++]=instr-'0';
		}else if(sp-1<0){
			fputs("stack underflow\n",stderr);
			continue;
		}
		else if(instr=='\n')printf("%d\n",stack[--sp]);
		else if(sp-2<0){
			fputs("stack underflow\n",stderr);
			continue;
		}
		if(instr=='+')stack[sp-2]+=stack[sp-1],sp--;
		if(instr=='-')stack[sp-2]-=stack[sp-1],sp--;
		if(instr=='*')stack[sp-2]*=stack[sp-1],sp--;
		if(instr=='/')stack[sp-2]/=stack[sp-1],sp--;
		if(instr=='%')stack[sp-2]%=stack[sp-1],sp--;
	}
}

[happyjoker]

thx all ...
thats vary good bro thx