tasks a-s

Task/Perfect-numbers/C/perfect-numbers-1.c

@@ -0,0 +1,27 @@
+#include "stdio.h"
+#include "math.h"
+
+int perfect(int n) {
+    int max = (int)sqrt((double)n) + 1;
+    int tot = 1;
+    int i;
+
+    for (i = 2; i < max; i++)
+        if ( (n % i) == 0 ) {
+            tot += i;
+            int q = n / i;
+            if (q > i)
+                tot += q;
+        }
+
+    return tot == n;
+}
+
+int main() {
+    int n;
+    for (n = 2; n < 33550337; n++)
+        if (perfect(n))
+            printf("%d\n", n);
+
+    return 0;
+}

Task/Perfect-numbers/C/perfect-numbers-2.c

@@ -0,0 +1,15 @@
+int main()
+{
+	int j;
+	ulong fac[10000], n, sum;
+
+	sieve();
+
+	for (n = 2; n < 33550337; n++) {
+		j = get_factors(n, fac) - 1;
+		for (sum = 0; j && sum <= n; sum += fac[--j]);
+		if (sum == n) printf("%lu\n", n);
+	}
+
+	return 0;
+}