Cannot output an array in C programming? - c

Question

I cannot seem to output a string or an integer array correctly in C programming.
My issue, is that the strings are stored in the array, I just cannot get them OUT of the array and to the output.
When I manually enter the positions (like Array[0]), it properly outputs.
However, the final loop fails to output any of my array entries.
Why is this happening?
Thanks in advance for all replies!
Here is the code:
#include<unistd.h>
#include<stdio.h>
#include<stdlib.h>
#include <string.h>
main (void)
{
int memory_start;
int memory_end;
int num_jobs;
printf("Enter the starting memory location to be used : ");
scanf("%d", &memory_start);
printf("\nEnter the ending memory location to be used : ");
scanf("%d", &memory_end);
printf("\nHow many jobs will be assigned to the memory locations? \n");
scanf("%d", &num_jobs);
int mem_size = memory_end - memory_start;
int mem_size_init = memory_end - memory_start;
char names[10][20];
int sizes[num_jobs];
int mem_st[10];
int mem_end[10];
int x;
int y;
int z;
int temp_size = 0;
int prev_temp_size;
char temp_name[20];
for(x=0; x<num_jobs; x++)
{
prev_temp_size = prev_temp_size + temp_size;
printf("\nEnter the size of the program (size > 0): ");
scanf("%d", &temp_size);
if( mem_size >= temp_size && temp_size > 0)
{
printf("\nEnter a program name (20 chars): %s", names[1]);
scanf("%s", &temp_name);
if(strlen(temp_name) <= 20)
{
strcpy(names[x], temp_name);
// names[x] = temp_name;
sizes[x] = temp_size;
mem_size = mem_size - temp_size;
mem_st[x] = prev_temp_size + memory_start;
mem_end[x] = temp_size + mem_st[x];
}
else
{
printf("\nProgram name is too long. Please re enter data.");
x--;
}
}
else
{
printf("\nMemory Size not supported (not enough space remaining).\nPlease re-enter data with a plausible memory request.");
printf("\nMemory size remaining: %d", mem_size);
x--;
}
}
printf("\nYour data is as follows: \n");
printf("\nYour initial memory size is: %d", mem_size_init);
printf("\nYour unused memory size is: %d", mem_size);
for(y=0; y<num_jobs; y++)
{
printf("Program: %s", names[y]);
printf("\n", names[y], " memory size is as follows: \n", "memory start: %d", mem_st[y], " memory end: %d", mem_end[y]);
}
}

Answer 1

Here is the corrected code:
#include<unistd.h>
#include<stdio.h>
#include<stdlib.h>
#include <string.h>
main (void)
{
int memory_start;
int memory_end;
int num_jobs;
printf("Enter the starting memory location to be used : ");
scanf("%d", &memory_start);
printf("\nEnter the ending memory location to be used : ");
scanf("%d", &memory_end);
printf("\nHow many jobs will be assigned to the memory locations? ");
scanf("%d", &num_jobs);
int mem_size = memory_end - memory_start;
int mem_size_init = memory_end - memory_start;
char names[10][20];
int sizes[num_jobs];
int mem_st[10];
int mem_end[10];
int x;
int y;
int z;
int temp_size = 0;
int prev_temp_size;
char temp_name[20];
for(x=0; x<num_jobs; x++)
{
prev_temp_size = prev_temp_size + temp_size;
printf("\nEnter the size of the program (size > 0): ");
scanf("%d", &temp_size);
if( mem_size >= temp_size && temp_size > 0)
{
printf("\nEnter a program name (20 chars): ");
scanf("%s", temp_name);
getchar();
if(strlen(temp_name) <= 20)
{
strcpy(names[x], temp_name);
sizes[x] = temp_size;
mem_size = mem_size - temp_size;
mem_st[x] = prev_temp_size + memory_start;
mem_end[x] = temp_size + mem_st[x];
}
else
{
printf("\nProgram name is too long. Please re enter data.");
x--;
}
}
else
{
printf("\nMemory Size not supported (not enough space remaining).\nPlease re-enter data with a plausible memory request.");
printf("\nMemory size remaining: %d", mem_size);
x--;
}
}
printf("\nYour data is as follows: \n");
printf("\nYour initial memory size is: %d", mem_size_init);
printf("\nYour unused memory size is: %d\n", mem_size);
for(y=0; y<num_jobs; y++)
{
printf("\nProgram: %s\n", names[y]);
printf("\nmemory size is as follows:\nmemory start: %d memory end: %d\n", mem_st[y], mem_end[y]);
}
}
Apart from changes in formatting the output, major changes are:
Removed the & in scanf("%s", &temp_name); because, the name of an array already returns a reference to its first element.
Added a getchar(); after scanf("%s", temp_name); because after reading in a string an extra \n remains in the stream, which causes the next scanf to fail.
This:
printf("\n", names[y], " memory size is as follows: \n", "memory start: %d", mem_st[y], " memory end: %d", mem_end[y]);
is not how a format specifier is prepared, all variables need to be placed at the end, after a single format specifier string.

Answer 2

The last loop is the issue.
for(y=0; y<num_jobs; y++)
{
printf("Program: %s", names[y]);
printf("\n memory size is as follows: ");
printf("\n memory start: %d memory end: %d", mem_st[y], mem_end[y]);
}
In C, the variables are given at the end of the printf. Also you are printing names two times, which i guess you don't want.