Learn to Program with C_ Learn to Program using the Popular C Programming Language ( PDFDrive )

Chapter 4 ■ Programs with Selection Logic
We find the sum by adding the two meter values and adding the two centimeter values. If the
centimeter value is less than 100, there is nothing more to do. But if it is not, we must subtract 100
from it and add 1 to the meter value. This logic is expressed as follows:
m = sum of meter values
cm = sum of centimeter values
if cm >= 100 then
subtract 100 from cm
add 1 to m
endif
As a boundary case, we must check that our program works if cm is exactly 100. As an exercise,
verify that it does.
Program P4.2 solves the problem as described.
Program P4.2
//find the sum of two lengths given in meters and cm
#include <stdio.h>
int main() {
int m1, cm1, m2, cm2, mSum, cmSum;
printf("Enter values for m and cm: ");
scanf("%d %d", &m1, &cm1);
printf("Enter values for m and cm: ");
scanf("%d %d", &m2, &cm2);
mSum = m1 + m2; //add the meters
cmSum = cm1 + cm2; //add the centimeters
if (cmSum >= 100) {
cmSum = cmSum - 100;
mSum = mSum + 1;
}
printf("\nSum is %dm %dcm\n", mSum, cmSum);
}
We use the variables m1 and cm1 for the first length, m2 and cm2 for the second length, and mSum
and cmSum for the sum of the two lengths.
The program assumes that the centimeter part of the given lengths is less than 100 and it
works correctly if this is so. But what if the lengths were 3m 150cm and 2m 200cm?
The program will print 6m 250cm. (As an exercise, follow the logic of the program to see why.)
While this is correct, it is not in the correct format since we require the centimeter value to be
less than 100. We can modify our program to work in these cases as well by using integer division
and % (the remainder operator).
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