date and time created 82/10/24 18:24:51 by mckusick

SCCS-vsn: games/arithmetic/arithmetic.c 4.1

diff --git a/usr/src/games/arithmetic/arithmetic.c b/usr/src/games/arithmetic/arithmetic.c
new file mode 100644 (file)
index 0000000..20288a5
--- /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();
+}
+