You are !o code and execute a C program to input narnes ard addresses t]rat are in alphabctic order and output the names and addresses to a new file in zip code order. Maxirnum of 50 names. lfre program should be modularize d and rvell documented. You must use a stnrcnrre for the names and acldress information. Allocate storage dlnamicrlly for each sruc0.rre. Use I/O redirection for the input and ouputfilcs. This program mustbe done with ar array of pointers to structures. Do notuse art uray o[ stmcnrres. This progarn MUST use multiple filc format You may use slring handling functions for tiris lab.

#define MAX 50

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

struct address

{

char name[MAX];

char street[MAX];

char city[MAX];

char zip[10];

};

void in(struct address *, int *);

void sort(struct address *, int);

void out(struct address *, int);

int main(){

struct address *ADDRESS = (struct address *)malloc(50*sizeof(struct address));

int n=0;

in(ADDRESS, &n);

sort(ADDRESS, n);

out(ADDRESS, n);

}

void in(struct address *ADDRESS, int *num)

{

FILE *fp;

char fname[MAX];

printf("Enter input file name: ");

scanf("%s", fname);

fp = fopen(fname, "r");

if (fp == NULL)

{

printf("Unable to open file");

exit(1);

}

int a = 0;

while (!feof(fp))

{

//ADDRESS = (struct address *)realloc(ADDRESS, (a + 1) * sizeof(struct address));

if(a>=50)

break;

fscanf(fp, "\n%[^\n]s", (ADDRESS+a)->name);

fscanf(fp, "\n%[^\n]s", (ADDRESS+a)->street);

fscanf(fp, "\n%[^\n]s", (ADDRESS+a)->city);

fscanf(fp, "\n%[^\n]s", (ADDRESS+a)->zip);

a++;

}

printf("Successfully %d read from file\n", a);

*num = a;

}

void sort(struct address *ADDRESS, int num){

int i, j;

for(i=0; i<num; i++){

for(j=i+1; j<num;j++){

if(strcmp((ADDRESS+i)->zip, (ADDRESS+j)->zip)>0){

struct address t = *(ADDRESS+i);

*(ADDRESS+i) = *(ADDRESS+j);

*(ADDRESS+j) = t;

}

}

}

}

void out(struct address *ADDRESS, int num)

{

FILE *fp;

char fname[MAX];

printf("Enter output file name: ");

scanf("%s", fname);

fp = fopen(fname, "w");

if (fp == NULL)

{

printf("Unable to open file");

exit(1);

}

int a;

for(a=0; a<num; a++)

{

fprintf(fp, "%s\n", (ADDRESS+a)->name);

fprintf(fp, "%s\n", (ADDRESS+a)->street);

fprintf(fp, "%s\n", (ADDRESS+a)->city);

fprintf(fp, "%s\n", (ADDRESS+a)->zip);  

}

printf("Successfully %d Write to file\n", a);

fclose(fp);

}

Explanation: