Operator precedence

#include<stdio.h> 
#include<string.h> 
#include<stdlib.h>
char *input; 
int i=0; 
char lasthandle[6],stack[50],handles[][5]={")E(","E*E","E+E","i","E^E"}; 
//(E) becomes )E( when pushed to stack 
int top=0,l; 
char prec[9][9]={ 
 //input/ 
 /*stack + - * / ^ i ( ) $ */ 
 /* + */ '>', '>','<','<','<','<','<','>','>', 
 /* - */ '>', '>','<','<','<','<','<','>','>', 
 /* * */ '>', '>','>','>','<','<','<','>','>', 
 /* / */ '>', '>','>','>','<','<','<','>','>', 
 /* ^ */ '>', '>','>','>','<','<','<','>','>', 
 /* i */ '>', '>','>','>','>','e','e','>','>', 
 /* ( */ '<', '<','<','<','<','<','<','>','e', 
 /* ) */ '>', '>','>','>','>','e','e','>','>', 
 /* $ */ '<', '<','<','<','<','<','<','<','>', 
};
int getindex(char c)
{ 
switch(c) 
 { 
 case '+':return 0; 
 case '-':return 1; 
 case '*':return 2; 
 case '/':return 3; 
 case '^':return 4; 
 case 'i':return 5; 
 case '(':return 6; 
 case ')':return 7; 
 case '$':return 8; 
 } 
} 
int shift() 
{ 
stack[++top]=*(input+i++); 
stack[top+1]='\0'; 
} 
int reduce() 
{ 
int i,len,found,t; 
for(i=0;i<5;i++)//selecting handles 
 { 
 len=strlen(handles[i]); 
 if(stack[top]==handles[i][0]&&top+1>=len) 
 { 
 found=1; 
 for(t=0;t<len;t++) 
 { 
 if(stack[top-t]!=handles[i][t]) 
 { 
 found=0; 
 break; 
 } 
 } 
 if(found==1) 
 { 
 stack[top-t+1]='E'; 
 top=top-t+1; 
 strcpy(lasthandle,handles[i]);
 stack[top+1]='\0'; 
 return 1;//successful reduction 
 } 
 } 
 } 
return 0; 
} 
void dispstack() 
{ 
int j;
for(j=0;j<=top;j++) 
 printf("%c",stack[j]); 
} 
void dispinput() 
{ 
int j;
for(j=i;j<l;j++) 
 printf("%c",*(input+j)); 
} 
int main() 
{ 
int j;
input=(char*)malloc(50*sizeof(char)); 
printf("\nEnter the string\n"); 
scanf("%s",input); 
input=strcat(input,"$"); 
l=strlen(input); 
strcpy(stack,"$"); 
printf("\nSTACK\tINPUT\tACTION"); 
while(i<=l) 
 { 
 shift(); 
 printf("\n"); 
 dispstack(); 
 printf("\t"); 
 dispinput(); 
 printf("\tShift"); 
 if(prec[getindex(stack[top])][getindex(input[i])]=='>') 
 { 
 while(reduce()) 
 { 
 printf("\n");
 dispstack(); 
 printf("\t"); 
 dispinput(); 
 printf("\tReduced: E->%s",lasthandle); 
 } 
 } 
 } 
if(strcmp(stack,"$E$")==0) 
 printf("\nAccepted;"); 
else 
 printf("\nNot Accepted;"); 
return 0;
}