Post Transition in C






#include <stdio.h>
#include <stdlib.h>
#define MAX_STRING_LENGTH 6
/*****Aakash Vikrant
**Kiet Group of Institutions**/
struct package
{
    char* id;
    int weight;
};
typedef struct package package;
struct post_office
{
    int min_weight;
    int max_weight;
    package* packages;
    int packages_count;
};
typedef struct post_office post_office;
struct town
{
    char* name;
    post_office* offices;
    int offices_count;
};
typedef struct town town;
void print_all_packages(town t) 
{
    printf("%s:\n", t.name);
    for (int i = 0; i < t.offices_count; i++) 
  {
        printf("\t%d:\n", i);
        for (int j = 0; j < t.offices[i].packages_count; j++) 
     {
            printf("\t\t%s\n", t.offices[i].packages[j].id);

  }

    }
}
int is_movable(post_office po, int w) 
{
    if (w >= po.min_weight && w <= po.max_weight)
        return 1;
    else
        return 0;
}
void send_all_acceptable_packages(town *s, int si, town *t, int ti) 
{
    int i, j;
    i = 0;
    while (i < s->offices[si].packages_count) 
   {
        if (is_movable(t->offices[ti], s->offices[si].packages[i].weight)) 
    {
            int *tp = &t->offices[ti].packages_count;
            t->offices[ti].packages = (package *) realloc(t->offices[ti].packages, (*tp+1) * sizeof(package));
            t->offices[ti].packages[(*tp)++] = s->offices[si].packages[i];
            int *sp = &s->offices[si].packages_count;
            for (j = i; j < *sp-1; j++) 
           {
                s->offices[si].packages[j] = s->offices[si].packages[j+1];
            }
            s->offices[si].packages = (package *) realloc(s->offices[si].packages, (*sp-1) * sizeof(package));
            (*sp)--;
        }
        else i++;
    }
}
town town_with_most_packages(town *towns, int towns_count) 
{
    int max = 0 , r = 0, i;
    for (i = 0; i < towns_count; i++) 
   {
        int packages_count = 0;
        for (int j = 0; j < towns[i].offices_count; j++) 
       {
            packages_count += towns[i].offices[j].packages_count;
        }
        if (packages_count > max) 
       {
            max  = packages_count;
            r = i;
        }
    }
    return towns[r];
}
town *find_town(town *towns, int towns_count, char *name) 
{
    for (int i = 0; i < towns_count; i++) 
   {
        if (!strcmp(name, towns[i].name))
            return &towns[i];
    }
    return NULL;
}
int main()
{
    int towns_count;
    scanf("%d", &towns_count);
    town* towns = malloc(sizeof(town)*towns_count);
    for (int i = 0; i < towns_count; i++) 
  {
        towns[i].name = malloc(sizeof(char) * MAX_STRING_LENGTH);
        scanf("%s", towns[i].name);
        scanf("%d", &towns[i].offices_count);
        towns[i].offices = malloc(sizeof(post_office)*towns[i].offices_count);
        for (int j = 0; j < towns[i].offices_count; j++) 
   {
            scanf("%d%d%d", &towns[i].offices[j].packages_count, &towns[i].offices[j].min_weight, &towns[i].offices[j].max_weight);
            towns[i].offices[j].packages = malloc(sizeof(package)*towns[i].offices[j].packages_count);
            for (int k = 0; k < towns[i].offices[j].packages_count; k++) 
            {
                towns[i].offices[j].packages[k].id = malloc(sizeof(char) * MAX_STRING_LENGTH);
                scanf("%s", towns[i].offices[j].packages[k].id);
                scanf("%d", &towns[i].offices[j].packages[k].weight);
            }
        }
    }
    int queries;
    scanf("%d", &queries);
    char town_name[MAX_STRING_LENGTH];
    while (queries--) 
{
        int type;
        scanf("%d", &type);
        switch (type) 
  {
        case 1:
            scanf("%s", town_name);
            town* t = find_town(towns, towns_count, town_name);
            print_all_packages(*t);
            break;
        case 2:
            scanf("%s", town_name);
            town* source = find_town(towns, towns_count, town_name);
            int source_index;
            scanf("%d", &source_index);
            scanf("%s", town_name);
            town* target = find_town(towns, towns_count, town_name);