to add a new function is that each expression should start with-sharp and end with-sharp. Ask the boss to write the complete code.
this is main

-sharpinclude <stdio.h>
-sharpinclude <stdlib.h>
-sharpinclude <string.h>
-sharpinclude <math.h>
-sharpinclude "stack.h"


int main(void){
    int i,j,len,cnt;
    OPTR *st=(OPTR*)malloc(sizeof(OPTR));// 
    EXPT *nst=(EXPT*)malloc(sizeof(EXPT));// 
    char str[85];
    char out[85];//
    printf("\n"); 
    scanf("%s",str);// 
    nst->top=-1;
    st->top=-1;
    cnt=0;
    len=strlen(str);// 
    for(i=0;i<len;iPP){
        if(isnumber(str[i]))
            out[cntPP]=str[i];
        else{
            if(str[i]=="("||isempty(st)){
                push(st,str[i]);
                continue;
            }
            if(str[i]==")"){
                while(top(st)!="("){
                    out[cntPP]=top(st);
                    pop(st);
                }
                pop(st);
                continue;
            }
            while(!isempty(st)&&top(st)!="("&&priority(str[i])<=priority(top(st))){
                out[cntPP]=top(st);
                pop(st);
            }
            push(st,str[i]);// 
        }
    }
    //Out 
    while(!isempty(st)){
        out[cntPP]=top(st);
        pop(st);
    }
    out[cnt]="\0";
    for(i=0;i<cnt;PPi)
        printf("%c ",out[i]);
    printf("\n");
    for(i=0;i<cnt;iPP){
        if(isnumber(out[i])){
            npush(nst,out[i]);
            continue;
        }else if(out[i]=="+"){
            nst->data[nst->top-1]+=ntop(nst);
            npop(nst);
        }else if(out[i]=="-"){
            nst->data[nst->top-1]-=ntop(nst);
            npop(nst);
        }else if(out[i]=="*"){
            nst->data[nst->top-1]*=ntop(nst);
            npop(nst);
        }else if(out[i]=="/"){
            nst->data[nst->top-1]/=ntop(nst);
            npop(nst);
        }
        for(j=0;j<=nst->top;PPj)
            printf("%d ",nst->data[j]);
        for(j=i+1;j<cnt;PPj)
            printf("%c ",out[j]);
        printf("\n");

    }
    return 0;
}

this is stake

typedef struct{
    char data[85];
    int top;
}OPTR;
typedef struct{
    int data[85];
    int top;
}EXPT;
//  
bool isnumber(char ch){
    if(ch>="0"&&ch<="9")
        return true;
    else
        return false;
}
// 
bool isempty(OPTR *s){
    if(s->top==-1)
        return true;
    else
        return false;
}
//
void push(OPTR *s,char ch){
    s->data[PPs->top]=ch;
}
void npush(EXPT *s,char ch){
    s->data[PPs->top]=ch-"0";
}
// 
char pop(OPTR *s){
    return s->data[s->top--];
}
int npop(EXPT *s){
    return s->data[s->top--];
}
// 
int priority(char ch){
    if(ch=="(")
        return 0;
    if(ch=="+"||ch=="-")
        return 1;
    if(ch=="*"||ch=="/")
        return 2;

    return 0;
}
// 
char top(OPTR *s){
   return s->data[s->top];
}
// 
int ntop(EXPT *s){
    return s->data[s->top];
}