C: Loops for data triples using for

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C: Loops for data triples using while
C: Loops for data pairs using while (uses trailer loop, so cannot be expressed using for loop)

There are times when adjacent triples of data need to be considered or processed together.

The code below shows how to read in a series of integers and then add adjacent triples together.

In addition, the first value read is saved for processing later.

A header loop is used.

Consider the following sequence of integers.

8 6 4 10 5 2 Here is a sequence of lines highlighting each of the triples.

8 6 4

6 4 10

4 10 5

10 5 2

Here is the C code.

#include <stdio.h>

int main() {
	int leftValue1;
	int middleValue1;
	int dataValue1;
	int rightValue1;
	int dataLen1;
	int triplePos1;
	int firstValue1;
	scanf("%d",&dataLen1);
	triplePos1 = 0;
	// prime the values to avoid errors
	firstValue1 = 0;
	leftValue1 = 0;
	middleValue1 = 0;
	rightValue1 = 0;
	for (int dataPos1=0; dataPos1<dataLen1; dataPos1++) {
		scanf("%d",&dataValue1);
		printf("\n");
		printf("Data value #%d is %d\n",dataPos1,dataValue1);
		if (dataPos1 == 1) {
			firstValue1 = dataValue1;
			}
		rightValue1 = dataValue1;
		if (dataPos1 > 2) {
			triplePos1 += 1;
			printf("Triple #%d is %d , %d , %d.\n",triplePos1,leftValue1,middleValue1,rightValue1);
			}
		leftValue1 = middleValue1;
		middleValue1 = rightValue1;
		}
	printf("\n");
	printf("Data values processed: %d\n",dataLen1);
	printf("Triples processed: %d\n",triplePos1);
	printf("The first data value was %d\n",firstValue1);
	return 0;
	}

Here are some examples of input and output for the above program code.

Here is an example input.

For the above example input, here is the expected output.

Data value #0 is 8

Data value #1 is 6

Data value #2 is 4

Data value #3 is 10
Triple #1 is 6 , 4 , 10.

Data value #4 is 5
Triple #2 is 4 , 10 , 5.

Data value #5 is 2
Triple #3 is 10 , 5 , 2.

Data values processed: 6
Triples processed: 3
The first data value was 6

Here is an example input.

For the above example input, here is the expected output.

Data value #0 is 7

Data value #1 is 3

Data value #2 is 5

Data value #3 is 2
Triple #1 is 3 , 5 , 2.

Data value #4 is 8
Triple #2 is 5 , 2 , 8.

Data values processed: 5
Triples processed: 2
The first data value was 3