From ec93545d1d36a59cfa7e36fa2efccf1dbea6e168 Mon Sep 17 00:00:00 2001
From: Kirk McKusick <mckusick@ucbvax.Berkeley.EDU>
Date: Mon, 25 Oct 1982 02:24:51 -0800
Subject: [PATCH] date and time created 82/10/24 18:24:51 by mckusick

SCCS-vsn: games/arithmetic/arithmetic.c 4.1
---
 usr/src/games/arithmetic/arithmetic.c | 218 ++++++++++++++++++++++++++
 1 file changed, 218 insertions(+)
 create mode 100644 usr/src/games/arithmetic/arithmetic.c

diff --git a/usr/src/games/arithmetic/arithmetic.c b/usr/src/games/arithmetic/arithmetic.c
new file mode 100644
index 0000000000..20288a57a2
--- /dev/null
+++ b/usr/src/games/arithmetic/arithmetic.c
@@ -0,0 +1,218 @@
+
+static char sccsid[] = "	arithmetic.c	4.1	82/10/24	";
+
+#include <stdio.h>
+#include <signal.h>
+#define	MAX	100
+
+char	types[10];
+int	right[MAX];
+int	left[MAX];
+int	rights;
+int	wrongs;
+long	stvec;
+long	etvec;
+long	dtvec;
+
+main(argc,argv)
+char	*argv[];
+{
+	int range, k, dif, l;
+	char line[100];
+	int ans,pans,i,j,t;
+	char	dir,sense;
+	extern	delete();
+
+	signal(SIGINT, delete);
+
+	range = 11;
+	dif = 0;
+	while(argc > 1) {
+		switch(*argv[1]) {
+		case '+':
+		case '-':
+		case 'x':
+		case '/':
+			while(types[dif] = argv[1][dif])
+				dif++;
+			break;
+
+		default:
+			range = getnum(argv[1]) + 1;
+		}
+		argv++;
+		argc--;
+	}
+	if(range > MAX) {
+		printf("Range is too large.\n");
+		exit();
+	}
+
+	if(dif == 0) {
+		types[0] = '+';
+		types[1] = '-';
+		dif = 2;
+	}
+
+	for(i = 0; i < range; i++) {
+		left[i] = right[i] = i;
+	}
+	time(&stvec);
+	k = stvec;
+	srand(k);
+	k = 0;
+	l = 0;
+	goto start;
+
+loop:
+	if(++k%20 == 0)
+		score();
+
+start:
+	i = skrand(range);
+	j = skrand(range);
+	if(dif > 1)
+		l = random(dif);
+
+	switch(types[l]) {
+		case '+':
+		default:
+			ans = left[i] + right[j];
+			printf("%d + %d =   ", left[i], right[j]);
+			break;
+
+		case '-':
+			t = left[i] + right[j];
+			ans = left[i];
+			printf("%d - %d =   ", t, right[j]);
+			break;
+
+		case 'x':
+			ans = left[i] * right[j];
+			printf("%d x %d =   ", left[i], right[j]);
+			break;
+
+		case '/':
+			while(right[j] == 0)
+				j = random(range);
+			t = left[i] * right[j] + random(right[j]);
+			ans = left[i];
+			printf("%d / %d =   ", t, right[j]);
+			break;
+	}
+
+
+loop1:
+	getline(line);
+	dtvec += etvec - stvec;
+	if(line[0]=='\n') goto loop1;
+	pans = getnum(line);
+	if(pans == ans) {
+		printf("Right!\n");
+		rights++;
+		goto loop;
+	}
+	else {
+		printf("What?\n");
+		wrongs++;
+		if(range >= MAX)	goto loop1;
+		left[range] = left[i];
+		right[range++] = right[j];
+		goto loop1;
+	}
+}
+
+getline(s)
+char *s;
+{
+	register char	*rs;
+
+	rs = s;
+
+	while((*rs = getchar()) == ' ');
+	while(*rs != '\n')
+		if(*rs == 0)
+			exit();
+		else if(rs >= &s[99]) {
+			while((*rs = getchar()) != '\n')
+				if(*rs == '\0')	exit();
+		}
+		else
+			*++rs = getchar();
+	while(*--rs == ' ')
+		*rs = '\n';
+}
+
+getnum(s)
+char *s;
+{
+	int	a;
+	char	c;
+
+	a = 0;
+	while((c = *s++) >= '0' && c <= '9') {
+		a = a*10 + c - '0';
+	}
+	return(a);
+}
+
+int arand;
+
+srand(n)
+{
+	arand = n&077774 | 01;
+}
+
+rand()		/*uniform on 0 to 2**13-1*/
+{
+
+	arand *= 3125;
+	arand &= 077777;
+	return(arand/4);
+}
+
+random(range)
+{
+	return(hmul(rand(), 8*range));
+}
+
+skrand(range){
+int temp;
+	temp = rand() + rand();
+	if(temp >017777) temp = 040000 - temp;
+	return(hmul(temp,8*range));
+	}
+
+/* 'hmul' returns the upper 16 bits of the product, where the operands
+   are assumed to be 16-bit integers. It replaces an old PDP-11 
+   assembler language subroutine. -- dks.
+*/
+hmul(a,b) { return(a*b >> 16); }
+score()
+{
+	time(&etvec);
+
+	printf("\n\nRights %d; Wrongs %d; Score %d%%\n", rights, wrongs,
+		(rights * 100)/(rights + wrongs));
+
+	if(rights == 0)	return;
+	printf("Total time %ld seconds; %.1f seconds per problem\n\n\n",
+		etvec - stvec,
+		(etvec - stvec) / (rights + 0.));
+
+	sleep(3);
+	time(&dtvec);
+	stvec += dtvec - etvec;
+	return(0);
+}
+
+delete()
+{
+	if(rights + wrongs == 0.) {
+		printf("\n");
+		exit();
+	}
+	score();
+	exit();
+}
+
-- 
2.20.1