﻿ C : In an array, find where the sequence 1, 2, 3 appears # C Exercises: Check whether the sequence of numbers 1, 2, 3 appears in a given array of integers somewhere

## C-programming basic algorithm: Exercise-14 with Solution

Write a C program to check whether the sequence of numbers 1, 2, 3 appears in a given array of integers somewhere.

C Code:

``````#include <stdio.h>
#include <stdlib.h>
int main(void){
int arr_size;
int array1[] = {1,1,2,3,1};
arr_size = sizeof(array1)/sizeof(array1);
printf("%d",test(array1, arr_size));
int array2[] = {1,1,2,4,1};
arr_size = sizeof(array2)/sizeof(array2);
printf("\n%d",test(array2, arr_size));
int array3[] = {1,2,2,1,2,3};
arr_size = sizeof(array3)/sizeof(array3);
printf("\n%d",test(array3, arr_size));
}
int test(int nums[], int arr_size)
{
for (int i = 0; i < arr_size-1; i++)
{
if (nums[i] == 1 && nums[i + 1] == 2 && nums[i + 2] == 3)
return 1;
}
return 0;
}
``````

Sample Output:

```1
0
1
```

Pictorial Presentation: Flowchart: C Programming Code Editor:

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## C Programming: Tips of the Day

Why doesn't a+++++b work?

printf("%d",a+++++b); is interpreted as (a++)++ + b according to the Maximal Munch Rule!.

++ (postfix) doesn't evaluate to an lvalue but it requires its operand to be an lvalue.

! 6.4/4 says the next preprocessing token is the longest sequence of characters that could constitute a preprocessing token"

Ref : https://bit.ly/3fdldUT