#include <stdio.h>
#include <stdbool.h>
/*
all_of: Check whether ALL elements in an array satisfy a predicate.
Parameters:
arr - pointer to the first element of the array
n - number of elements
pred - pointer to a predicate function taking an int and returning bool
Returns:
true - if every element satisfies pred
false - otherwise
Idiomatic C approach:
- Use a simple loop (fast, branch‑predictable).
- Stop early on first failure (efficient).
- Use function pointers for predicates.
*/
bool all_of(const int *arr, size_t n, bool (*pred)(int)) {
for (size_t i = 0; i < n; ++i) {
if (!pred(arr[i])) {
return false; // Early exit: one element failed the predicate
}
}
return true; // All elements satisfied the predicate
}
/*
Predicate:
Check if a number is positive.
*/
bool is_positive(int x) {
return x > 0;
}
/*
Predicate:
Check if a number is even.
*/
bool is_even(int x) {
return (x % 2) == 0;
}
int main(void) {
int data1[] = { 3, 5, 7, 9 };
int data2[] = { 2, 4, 6, 8 };
int data3[] = { 1, -2, 3, 4 };
size_t size1 = sizeof(data1) / sizeof(data1[0]);
size_t size2 = sizeof(data2) / sizeof(data2[0]);
size_t size3 = sizeof(data3) / sizeof(data3[0]);
printf("All positive in data1? %s\n",
all_of(data1, size1, is_positive) ? "true" : "false");
printf("All even in data2? %s\n",
all_of(data2, size2, is_even) ? "true" : "false");
printf("All positive in data3? %s\n",
all_of(data3, size3, is_positive) ? "true" : "false");
return 0;
}
/*
run:
All positive in data1? true
All even in data2? true
All positive in data3? false
*/
