#include <stdio.h>
#include <stdbool.h>
#include <stddef.h>
/*
is_sorted: Check whether an array is sorted in non-decreasing order.
Parameters:
arr - pointer to the first element of the array
n - number of elements
Returns:
true - if the array is sorted (each element <= next)
false - otherwise
Idiomatic C approach:
- Use a simple loop (fast and predictable).
- Compare each element with its successor.
- Stop immediately when a violation is found (efficient).
*/
bool is_sorted(const int *arr, size_t n) {
if (n < 2) {
return true; // Arrays of size 0 or 1 are trivially sorted
}
for (size_t i = 0; i < n - 1; ++i) {
if (arr[i] > arr[i + 1]) {
return false; // Early exit: found a descending pair
}
}
return true; // No violations found
}
int main(void) {
int data1[] = { 1, 2, 3, 4, 5 }; // sorted
int data2[] = { 5, 4, 3, 2, 1 }; // not sorted
int data3[] = { 2, 2, 3, 3, 4 }; // sorted (non-decreasing)
int data4[] = { 10 }; // trivially sorted
size_t size1 = sizeof(data1) / sizeof(data1[0]);
size_t size2 = sizeof(data2) / sizeof(data2[0]);
size_t size3 = sizeof(data3) / sizeof(data3[0]);
size_t size4 = sizeof(data4) / sizeof(data4[0]);
printf("data1 sorted? %s\n", is_sorted(data1, size1) ? "true" : "false");
printf("data2 sorted? %s\n", is_sorted(data2, size2) ? "true" : "false");
printf("data3 sorted? %s\n", is_sorted(data3, size3) ? "true" : "false");
printf("data4 sorted? %s\n", is_sorted(data4, size4) ? "true" : "false");
return 0;
}
/*
run:
data1 sorted? true
data2 sorted? false
data3 sorted? true
data4 sorted? true
*/
