Sifat's Assignment

#include<stdio.h>

typedef struct date
{
// DO NOT MAKE ANY CHANGE HERE
    int day;
    int month;
    int year;
} DATE;

typedef struct person
{
// DO NOT MAKE ANY CHANGE HERE
    char first_name[20];
    char last_name[20];
    DATE birth_date;
    long int nid;
    char address[200];
} PERSON;

void print_options()
{
// DO NOT MAKE ANY CHANGE HERE
    printf("************­********************­***********\n");
    printf("1: Calculating multiplication using recursion\n");
    printf("2: Testing symmetricity for a matrix\n");
    printf("3: Finding frequency of letters in a line\n");
    printf("4: Storing a person's information in a structure\n");
    printf("q: quit\n");
    printf("************­********************­***********\n");
    printf("Enter a option: ");
}

int recursion_task()
{
    int x,y;
    printf("\nEnter the first number: ");
    scanf("%d", &x);
    printf("Enter the second number: ");
    scanf("%d", &y);
    printf("Result is: %d", result(x,y));
    return 0;
}
int result (int n1,int n2)
{
    if(n2==0)
        return 0;
    if(n2>0)
        return (n1+result(n1,n2-1));
    if(n2<0)
        return -result(n1,-n2);
}
void array_task()
{
    int n, i, j, k;
    printf("Enter dimension of the matrix: ");
    scanf("%d", &n);
    int arr[n][n];
    printf("Enter the matrix:\n");
    for(i = 0; i < n; i++)
        for(j = 0; j < n; j++)
            scanf("%d", &arr[i][j]);
    int sym = 0;
    for(i = 0; i < n; i++)
    {
        for(j = 0; j < n; j++)
        {
            if(arr[i][j] == -arr[j][i])
                sym = -1;
            else if(arr[i][j] != arr[j][i])
                sym = 1;

        }
    }
    if(!sym)
        printf("Symmetric matrix\n");
    else if(sym == -1)
        printf("Skew-symmetric matrix\n");
    else
        printf("Asymmetric matrix\n");
}

void string_task()
{
    char str[1000];
    printf("Enter the line: ");
    gets(str);
    int len = strlen(str);
    int occ[30];
    for(int i = 0; i < 30; i++)
        occ[i] = 0;
    for(int i = 0; i < len; i++)
    {
        int id = str[i] - 'A';
        occ[id]++;
    }
    for(int i = 0; i < 26; i++)
    {
        printf("%c\t%d\t\t", 'A'+i, occ[i]);
    }
}

void structure_task()
{
    PERSON temp;
    printf("Provide citizen Information....\n\n");
    printf("First Name: ");
    scanf("%s", temp.first_name);
    printf("Last Name: ");
    scanf("%s", temp.last_name);
    printf("\nDate of Birth...\n\n");
    printf("Date: ");
    scanf("%d", &temp.birth_date.day);
    printf("Month: ");
    scanf("%d", &temp.birth_date.month);
    printf("Year: ");
    scanf("%d", &temp.birth_date.year);
    printf("\nNID: ");
    scanf("%lld", &temp.nid);
    printf("\nAddress: ");
    gets(temp.address);
    gets(temp.address);
    printf("**************************************\n");
    printf("%s %s\n", temp.first_name, temp.last_name);
    printf("Date of Birth: %d-%d-%d\n", temp.birth_date.day, temp.birth_date.month, temp.birth_date.year);
    int cnt1 = 0, cnt2 = 0, temp1, temp2;
    temp1 = temp.birth_date.day, temp2 = temp.birth_date.month;
    while(temp1)
    {
        cnt1++;
        temp1 /= 10;
    }
    while(temp2)
    {
        cnt2++;
        temp2 /= 10;
    }
    printf("NID: %d ", temp.birth_date.year);
    if(cnt2 == 1)
        printf("0");
    printf("%d", temp.birth_date.month);
    if(cnt1 == 1)
        printf("0");
    long long int id = temp.nid;
    printf("%d %I64d\n", temp.birth_date.day, id);
    printf("Address: %s\n", temp.address);
    printf("**************************************\n");
}


int main()
{
// DO NOT MAKE ANY CHANGE HERE
    char op,c;
    do
    {
        print_options();
        fflush(stdin); //If we don't clear the standard input, we will keep getting '\n' after the first operation in op which will cause the wrong operation
        scanf("%c%c", &op,&c);
        switch(op)
        {
        case '1':
            recursion_task();
            break;
        case '2':
            array_task();
            break;
        case '3':
            string_task();
            break;
        case '4':
            structure_task();
            break;
        case 'q':  //for not showing default in case of quit
            break;
        case 'Q':  //for not showing default in case of quit
            break;
        default:
            printf("\nEnter a valid option\n");
            break;

        }
        printf("\n\n");
    }
    while(op!='q' && op!='Q');

    return 0;
}