Post_Transition

#include <stdio.h>
#include <stdlib.h>
#define MAX_STRING_LENGTH 6

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);
    }
}

void send_all_acceptable_packages(town* source, int source_office_index, town* target, int target_office_index) {
    post_office *src = source->offices+source_office_index;
    post_office *dst = target->offices+target_office_index;
    package buff[src->packages_count]; int buff_size = 0;
    for(int i = 0; i < src->packages_count;){
        if(src->packages[i].weight >= dst->min_weight && src->packages[i].weight <= dst->max_weight){
            buff[buff_size++] = src->packages[i];
            for(int j = i; j < src->packages_count-1; j++)
                src->packages[j] = src->packages[j+1];
            src->packages_count--;
        }
        else i++;
    }
    dst->packages = realloc(dst->packages, (dst->packages_count+buff_size)*sizeof(package));
    for(int i = 0; i < buff_size; i++){
        dst->packages[dst->packages_count++] = buff[i];
    }
}

town town_with_most_packages(town* towns, int towns_count) {
    town maxt = *towns; int max = 0;
    for(int i = 0; i < towns->offices_count; i++){
        max += towns->offices[i].packages_count;
    } towns++; towns_count--;
    while(towns_count){
        int sum = 0;
        for(int i = 0; i < towns->offices_count; i++){
            sum += towns->offices[i].packages_count;
        }
        if(sum > max) {
            max = sum;
            maxt = *towns;
        }
        towns++; towns_count--;
    }
    return maxt;
}

town* find_town(town* towns, int towns_count, char* name) {
    while(towns_count){
        if(!strcmp(towns->name,name)){
            return towns;
        }
        towns++; towns_count--;
    }
    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);
			int target_index;
			scanf("%d", &target_index);
			send_all_acceptable_packages(source, source_index, target, target_index);
			break;
		case 3:
			printf("Town with the most number of packages is %s\n", town_with_most_packages(towns, towns_count).name);
			break;
		}
	}
	return 0;
}