A-M baby

Task/Fibonacci-sequence/C/fibonacci-sequence-1.c

@@ -0,0 +1,3 @@
+long long unsigned fib(unsigned n) {
+    return n < 2 ? n : fib(n - 1) + fib(n - 2);
+}

Task/Fibonacci-sequence/C/fibonacci-sequence-2.c

@@ -0,0 +1,10 @@
+long long unsigned fib(unsigned n) {
+    long long unsigned last = 0, this = 1, new, i;
+    if (n < 2) return n;
+    for (i = 1 ; i < n ; ++i) {
+        new = last + this;
+        last = this;
+        this = new;
+    }
+    return this;
+}

Task/Fibonacci-sequence/C/fibonacci-sequence-3.c

@@ -0,0 +1,6 @@
+#include <tgmath.h>
+#define PHI ((1 + sqrt(5))/2)
+
+long long unsigned fib(unsigned n) {
+    return floor( (pow(PHI, n) - pow(1 - PHI, n))/sqrt(5) );
+}

Task/Fibonacci-sequence/C/fibonacci-sequence-4.c

@@ -0,0 +1,37 @@
+#include <stdio.h>
+typedef enum{false=0, true=!0} bool;
+typedef void iterator;
+
+#include <setjmp.h>
+/* declare label otherwise it is not visible in sub-scope */
+#define LABEL(label) jmp_buf label; if(setjmp(label))goto label;
+#define GOTO(label) longjmp(label, true)
+
+/* the following line is the only time I have ever required "auto" */
+#define FOR(i, iterator) { auto bool lambda(i); yield_init = (void *)&lambda; iterator; bool lambda(i)
+#define DO {
+#define     YIELD(x) if(!yield(x))return
+#define     BREAK    return false
+#define     CONTINUE return true
+#define OD CONTINUE; } }
+
+static volatile void *yield_init; /* not thread safe */
+#define YIELDS(type) bool (*yield)(type) = yield_init
+
+iterator fibonacci(int stop){
+    YIELDS(int);
+    int f[] = {0, 1};
+    int i;
+    for(i=0; i<stop; i++){
+        YIELD(f[i%2]);
+        f[i%2]=f[0]+f[1];
+    }
+}
+
+main(){
+  printf("fibonacci: ");
+  FOR(int i, fibonacci(16)) DO
+    printf("%d, ",i);
+  OD;
+  printf("...\n");
+}