Technical Stuff

Below is the complete working C source code for the simple calculator. Click here for the problem description. This programs takes the input file name as a command line argument and write the result in the output.dat in the current directory.

//
// main.c
// Calculator
//
// Created by chanduthedev on 4/18/13.
//
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
void add(int first, int second,FILE * ofp)
{
 printf("%d + %d = %d\n",first,second,first+second);
 fprintf(ofp,"%d + %d = %d\n",first,second,first+second);
 
}
void multiply(int first, int second,FILE *ofp)
{
 printf("%d * %d = %d\n",first,second,first * second);
 fprintf(ofp,"%d * %d = %d\n",first,second,first * second);
}
void substract(int first, int second, FILE *ofp)
{
 
 printf("%d - %d = %d\n",first,second,first-second);
 fprintf(ofp,"%d - %d = %d\n",first,second,first-second);
}
void divide(int first,int second, FILE * ofp)
{
 
 fprintf(ofp,"%d / %d = %d\n",first,second,first/second);
 printf("%d / %d = %d\n",first,second,first/second);
}
void toUpperCase(char ch, FILE * ofp)
{
 printf("%c ==> %c\n",ch,toupper(ch));
 fprintf(ofp,"%c ==> %c\n",ch,toupper(ch));
}
void toLowerCase(char ch,FILE * ofp)
{
 printf("%c ==> %c\n",ch,tolower(ch));
 fprintf(ofp,"%c ==> %c\n",ch,tolower(ch));
}
void printKthDigit(int val, int k,FILE * ofp)
{
 int i=1;
 int temp =val;
 while(temp >0)
 {
 if(i == k)
 {
 printf("%d (digit @ %d) ==> %d\n",val,k, temp%10);
 fprintf(ofp,"%d (digit @ %d) ==> %d\n",val,k, temp%10);
 break;
 };
 i++;
 temp = temp/10;
 }
 
}
void roundDecimal(double x, int n, FILE * ofp)
{
 char temp[32]="";
 
 double rounded = round(x);
 
 sprintf(temp,"%.*lf",n,rounded);
 printf("%lf (precision=%d) => %s\n",x,n,temp);
 fprintf(ofp,"%lf (precision=%d) => %s\n",x,n,temp);
 
}
void separte(double x , FILE * ofp)
{
 char temp[32]="";
 char sign;
 int intPart;
 int fraction;
 sprintf(temp,"%lf",x);
 
 sscanf(temp,"%d.%d",&intPart,&fraction);
 
 if(intPart > 0)
 sign = '+';
 else
 {
 sign = '-';
 intPart = -1 * intPart;
 }
 printf("%lf ==> sign=%c, integer=%d,fraction=%d\n",x, sign,intPart,fraction);
 fprintf(ofp,"%lf ==> sign=%c, integer=%d,fraction=%d\n",x, sign,intPart,fraction);
}
void partitionInteger(int i, int x, FILE * ofp)
{
 int j;
 int k;
 
 j = floor(x* i/100.0);
 
 k = i-j;
 
 printf("i=%d,x=%d ==> j=%d, k=%d \n",i,x,j,k);
 fprintf(ofp,"i=%d,x=%d ==> j=%d, k=%d \n",i,x,j,k);
}
void help( FILE * ofp)
{
 printf("\n *** Help Menu! See below for Calculator Commands: ***\n");
 printf("\n + i j ---> Add integers i and j \n");
 printf("\n * i j ---> Multiply integers i and j \n");
 printf("\n + -i j ---> Subtract integer j from i \n");
 printf("\n /i j ---> Divide integer i by j \n");
 printf("\n C Ch ---> Change character Ch to uppercase \n");
 printf("\n c Ch ---> Change character Ch to lowercase \n");
 printf("\n P i k ---> Print out the k-th digit of integer i \n");
 printf("\n R x i ---> Round double value x to i decimal places \n");
 printf("\n S x ---> Separate out the sign, integer part and fractional part of double value x \n");
 printf("\n D i x ---> Given integers i and x, print out two integers j and k, where the sum of j and k equals i, and when you take x'percent' of i and truncate it you get j \n");
 printf("\n H ---> view all commands \n");
 printf("\n Q ---> Quit program\n");
 
}
int main(int argc, const char * argv[])
{
 if(argc != 2)
 {
 printf("Usage ");
 exit(0);
 }
 
 const char * inFile=argv[1];
 
 char str[64];
 int lineNum=1;
 int first,second;
 double firstDouble;
 char ch;
 char outFile[]="outData.dat";
 
 FILE * ofp = fopen(outFile,"w");
 
 FILE * fp = fopen(inFile,"r");
 while(fgets(str,64,fp) != NULL)
 {
 if(lineNum == 1)
 {
 printf("Initial %s",str);
 }
 else
 {
 char * temp = str;
 char cmd = temp[0];
 temp++; //ignore command
 temp++; //ignore space;
 
 printf("CMD=%c : ",cmd);
 if(cmd == '+')
 {
 sscanf(temp,"%d %d",&first,&second);
 add(first,second,ofp);
 }
 else if (cmd == '*')
 {
 sscanf(temp,"%d %d",&first,&second);
 multiply(first,second,ofp);
 }
 else if (cmd == '-')
 {
 sscanf(temp,"%d %d",&first,&second);
 substract(first,second,ofp);
 }
 else if (cmd == '/')
 {
 sscanf(temp,"%d %d",&first,&second);
 divide(first,second,ofp);
 }
 else if (cmd == 'C')
 {
 sscanf(temp,"%c",&ch);
 toUpperCase(ch,ofp);
 }
 else if (cmd == 'c')
 {
 sscanf(temp,"%c",&ch);
 toLowerCase(ch,ofp);
 }
 else if (cmd == 'P')
 {
 sscanf(temp,"%d %d",&first, &second);
 printKthDigit(first,second,ofp);
 }
 else if (cmd == 'R')
 {
 sscanf(temp, "%lf %d",&firstDouble,&second);
 roundDecimal(firstDouble, second,ofp);
 }
 else if (cmd == 'S')
 {
 sscanf(temp,"%lf",&firstDouble);
 separte(firstDouble,ofp);
 }
 else if (cmd == 'D')
 {
 sscanf(temp,"%d %d",&first,&second);
 partitionInteger(first,second,ofp);
 }
 else if (cmd == 'H')
 {
 help(ofp);
 }
 else if (cmd == 'Q')
 {
 break;//quits
 }
 else
 {
 printf("Function Z not implemented yet!");
 }
 }
 lineNum++;
 }
 
 fclose(fp);
 fclose(ofp);
 return 0;
}

Input file format:

KING
H
+ 2 5
- 10 5
* 8 9
/ 92 3
c A
C b
P 56234 3
R 3.64195 2
S -51.235
D 50 10

OutPut:
2 + 5 = 7
10 - 5 = 5
8 * 9 = 72
92 / 3 = 30
A ==> a
b ==> B
56234 (digit @ 3) ==> 2
3.641950 (precision=2) => 4.00
-51.235000 ==> sign=-, integer=51,fraction=235000
i=50,x=10 ==> j=5, k=45

Labels: C program, Programming in C