What can I do to make it so my programs keeps the lowest number entered in a switch in a do while loop?

Question

I'm trying to get the numbers from the user, as many as they want to enter. In a menu. I have gotten everything I needed to do to work except for this lowest number thing. I'm not sure where to go from here. I don't know how I would get the number in the switch.

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#define PAUSE system("pause")
#define CLEAR system("cls")

main() {
    // Initialize variables
    char choice;
    int sum = 0;
    int avg = 0;
    int high = 0;
    int low = 0;
    int quit = 0;
    int i = 0;
    int num = 0;
    int j = 0;
    int prevNum;

    do{
        printf("What would you like to do\n"
        "A: enter an integer\n"
        "B: show sum\n" 
        "C: Show average\n" 
        "D: show Highest num\n" 
        "E: Show lowest\n" 
        "Q: quit\n");
        scanf("%c", &choice);
        CLEAR;

    switch (choice) {
    case 'A':
        printf("Enter an Integer\n");
        scanf("%i", &num);
        j++;
        sum = num + sum;

        if (num > high)
            high = num;

        PAUSE;
        break;

    case 'B':
        printf("The sum of al numbers entered is %i\n", sum);
        PAUSE;
        break;

    case 'C':
        avg = sum / j;
        printf("The average of all numbers entered is %i\n",avg);
        PAUSE;
        break;

    case 'D':
        printf("The Highest number entered is %i\n", high);
        PAUSE;
        break;

    case 'E':

        printf("The lowest number entered is %i\n", low);
        PAUSE;
        break;

    case 'Q':
        quit = 1;
        break;


    } // end switch

 } while (quit != 1);

PAUSE;
} // END MAIN

Answer 1

You can just use:

if (num < low) {
    low = num;
}

The only problem is the first number. Since you initialize low to 0 , any positive number the user enters will not be lower than this. You need to treat the first number specially. You can check the value of j for this.

Then in your A case, test this variable.

case 'A':
    printf("Enter an Integer\n");
    scanf("%i", &num);
    j++;
    sum = num + sum;

    if (j == 1 || num > high)
        high = num;
    if (j == 1 || num < low)
        low = num;

    PAUSE;
    break;

Answer 2

proper initialization is mandatory.

Suggest:

high should be initialized to INT_MIN.

low should be initialized to INT_MAX.

Note: Those macros are found in stdint.h.

then after the two lines:

if (num > high) 
    high = num; 

insert the two lines:

if(num < low) 
    low = num;