feat: ✨ add imperative solutions

Author: maxbarsukov

lib/largest_prime_factor/imperative.c

@@ -0,0 +1,31 @@
+#include <stdio.h>
+#include <assert.h>
+
+int is_prime(long long num) {
+    if (num <= 1) return 0;
+    for (long long i = 2; i * i <= num; i++) {
+        if (num % i == 0) return 0;
+    }
+    return 1;
+}
+
+long long largest_prime_factor(long long num) {
+    long long i;
+    for (i = 2; i * i <= num; i++) {
+        if (num % i == 0 && is_prime(i)) {
+            num /= i;
+            i--;
+        }
+    }
+    return num;
+}
+
+int main() {
+    long long num = 600851475143;
+    long long largest_factor = largest_prime_factor(num);
+
+    printf("The largest prime factor of %lld is %lld\n", num, largest_factor);
+    assert(largest_factor == 6857);
+
+    return 0;
+}

lib/number_spiral_diagonals/imperative.c

@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <assert.h>
+
+int main() {
+    int size = 1001;
+    int sum = 1;
+    int num = 1;
+    int increment = 2;
+
+    for (int i = 3; i <= size; i += 2) {
+        for (int j = 0; j < 4; j++) {
+            num += increment;
+            sum += num;
+        }
+        increment += 2;
+    }
+
+    printf("The sum of the numbers on the diagonals is %d\n", sum);
+    assert(sum == 669171001);
+
+    return 0;
+}