Data commit

Task/Isqrt-integer-square-root-of-X/C/isqrt-integer-square-root-of-x.c

@@ -0,0 +1,38 @@
+#include <stdint.h>
+#include <stdio.h>
+
+int64_t isqrt(int64_t x) {
+    int64_t q = 1, r = 0;
+    while (q <= x) {
+        q <<= 2;
+    }
+    while (q > 1) {
+        int64_t t;
+        q >>= 2;
+        t = x - r - q;
+        r >>= 1;
+        if (t >= 0) {
+            x = t;
+            r += q;
+        }
+    }
+    return r;
+}
+
+int main() {
+    int64_t p;
+    int n;
+
+    printf("Integer square root for numbers 0 to 65:\n");
+    for (n = 0; n <= 65; n++) {
+        printf("%lld ", isqrt(n));
+    }
+    printf("\n\n");
+
+    printf("Integer square roots of odd powers of 7 from 1 to 21:\n");
+    printf(" n |              7 ^ n | isqrt(7 ^ n)\n");
+    p = 7;
+    for (n = 1; n <= 21; n += 2, p *= 49) {
+        printf("%2d | %18lld | %12lld\n", n, p, isqrt(p));
+    }
+}