Question

9. The purpose of the following program is to generate 10 random integers, store them in an array, and then store in the freq frequency array, the number of occurrences of each number from 0 to 9. Can you find any errors in the program? If yes, correct them. #include <stdio.h> #include <stdlib.h> #include <time.h> #define SIZE 10 int main(void) int i, num, arr[SIZE], freq[SIZE]; srand (time (NULL)); arr[1] rand(); SIZE; for(i i 〈 i++) num arr[i]; freq[num]++; printf("InNumber occurrences In"); for(i = 0; ǐ 〈 SIZE; i++) printf("%d appears %d times\n", i, freq[i]); return 0;

Answer 1

1.The error is array freq have not been initialized zero(0).so freq[num]++ is not have meaning of increment freq[num].Then change the declaration of freq[SIZE] = {0}.

2.arr contains number out of [0,SIZE-1].Examplethe number is stored 20,and num becomes 20 and the statement freq[20]++;changes the content of memory location out of arr.This error can be corrected with if statement.

if(num>=0 && num<=SIZE-1)
{

freq[num]++;
}

Program:

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#define SIZE 10
int main(void)
{

//declaration of variables are i,num,arr,freq.
int i,num = 0,arr[SIZE],freq[SIZE]={0};
srand(time(NULL));
for(i=0;i<SIZE;i++)
arr[i] = rand();
//for(i=0;i<SIZE-1;i++)
if(num>=0 && num<=SIZE-1)
{
//num = arr[i];
freq[num]++;
}
printf("\nNumber occurances\n");
for(i=0;i<SIZE;i++)
printf("%d appears %d times\n",i,freq[i]);
return 0;
}

Output: