Thread: Subtracting one column in a 2d array from another?

I have a 2d array where I manage donations and requests for different foods. I output a menu to the user who picks the options to either make a donation, make a request, fulfill a request, or print a status report of all the donations and requests. What I'm having trouble with is the fulfilling requests option. When the user picks fulfill requests that means that the donations are supposed to be subtracted from the requests. For example if there are 10 donations for grains and 15 requests for grains then after picking fulfill request there should be 0 donations for grains and 5 requests for grains but I don't know how to make the program do that since the values are in a 5 row by 2 column array. The five rows correspond to the five foods and the two columns correspond to donations and requests, respectively. Anyone mind helping me out? Here's my code so far. Just disregard everything but the third case.

Code:

 #include <stdio.h>int main(){
    int foodbank[5][2]= {
    {0,0},
    {0,0},
    {0,0},
    {0,0},
    {0,0}
    };
    int choice, donation, request, donation_type, request_type;




    printf("Welcome to the Food Bank Management Program!\n");
    printf("What would you like to do?\n");
    printf("\t1. Enter a Donation\n");
    printf("\t2. Enter  a Request\n");
    printf("\t3. Fulfill Requests\n");
    printf("\t4. Print status report\n");
    printf("\t5. Exit \n");
    scanf("%d",&choice);


    while(choice!= 5){
        switch(choice){
        case 1: printf("What donation type would you like to enter?\n");
        printf("\t0. Protein\n");
        printf("\t1. Dairy\n");
        printf("\t2. Grains\n");
        printf("\t3. Vegetables\n");
        printf("\t4. Fruits\n");
        scanf("%d",&donation_type);


        if (donation_type == 0 ) {
            printf("How many would you like to enter?\n");
            scanf("%d",&donation);
            foodbank[0][0]+=donation;
            printf("Donation Added.\n");
            break;
        }


        else if (donation_type == 1 ) {
            printf("How many would you like to enter?\n");
            scanf("%d",&donation);
            foodbank[1][0]+=donation;
            printf("Donation Added.\n");
            break;
        }


        else if (donation_type == 2 ) {
            printf("How many would you like to enter?\n");
            scanf("%d",&donation);
            foodbank[2][0]+=donation;
            printf("Donation Added.\n");
            break;
        }


        else if (donation_type == 3 ) {
            printf("How many would you like to enter?\n");
            scanf("%d",&donation);
            foodbank[3][0]+=donation;
            printf("Donation Added.\n");
            break;
            }


        else if (donation_type == 4 )  {
            printf("How many would you like to enter?\n");
            scanf("%d",&donation);
            foodbank[4][0]+=donation;
            printf("Donation Added.\n");
            break;
        }


        else {
            printf("Invalid choice");
        }
        case 2: printf("What would you like to request?\n");
        printf("\t0. Protein\n");
        printf("\t1. Dairy\n");
        printf("\t2. Grains\n");
        printf("\t3. Vegetables\n");
        printf("\t4. Fruits\n");
        scanf("%d",&request_type);






           if (request_type == 0 ) {
            printf("How many would you like to request?\n");
            scanf("%d",&request);
            foodbank[0][1]+=request;
            printf("Request Added.\n");
            break;
        }


        else if (request_type == 1 ) {
            printf("How many would you like to request?\n");
            scanf("%d",&request);
            foodbank[1][1]+=request;
            printf("Request Added.\n");
            break;
        }


        else if (request_type == 2 ) {
            printf("How many would you like to request?\n");
            scanf("%d",&request);
            foodbank[2][1]+=request;
            printf("Request Added.\n");
            break;
        }


        else if (request_type == 3 ) {
            printf("How many would you like to request?\n");
            scanf("%d",&request);
            foodbank[3][1]+=request;
            printf("Request Added.\n");
            break;
            }


        else if (request_type == 4 )  {
            printf("How many would you like to request?\n");
            scanf("%d",&request);
            foodbank[4][1]+=request;
            printf("Request Added.\n");
            break;
        }


        else {
            printf("Invalid choice");


        }


        case 3: 
        




    }


    printf("What would you like to do?\n");
    printf("\t1. Enter a Donation\n");
    printf("\t2. Enter  a Request\n");
    printf("\t3. Fulfill Requests\n");
    printf("\t4. Print status report\n");
    printf("\t5. Exit \n");
    scanf("%d",&choice);
}


}