Added 'extra precision' (calculating 'e').

simmod/ass1/.gitignore

@@ -4,3 +4,4 @@ fp
 float_double
 report.pdf
 fd*
+pr

simmod/ass1/Makefile

@@ -3,7 +3,7 @@ FLAGS=-Wall -Wextra -std=c99 -pedantic -O0 -lm
 TYPES=float double LD
 OPS=ADD DIV MULT SQRT
 
-all: fp speed report.pdf fd
+all: fp speed report.pdf fd pr
 
 %.pdf: %.tex
 	pdflatex $^
@@ -19,6 +19,9 @@ speed: speed.c
 	done;
 	touch $@
 
+pr: extra_precision.o
+	$(CC) $(FLAGS) -o $@ $^
+
 fp: floating_point.o
 	$(CC) $(FLAGS) -o $@ $^
 

simmod/ass1/extra_precision.c

+#include <stdio.h>
+
+// Calculate 'e' using
+// e=1+1/1!+1/2!+1/3!+1/4!+...
+// 4! is 4x3x2x1. The series converges rapidly to e.
+// That series comes from this series:
+// ex=1+x/1!+x2/2!+x3/3!+x4/4!+...
+
+int fact(int x) {return x > 0 ? x * fact(x-1) : 1; }
+
+int main(void) {
+    printf("fact 8: %d\n", fact(8));
+    float e = 1;
+    for(int i = 1; i < 20; i++ ) {
+        e += 1.f / fact(i);
+    }
+    printf("approx. e: %.80f\n", e);
+    return 0;
+}