projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 42d6e430 BJ |
1 | #include "stdio.h" |
| 2 | #include "lrnref" | |
| 3 | ||
| 4 | int nsave = 0; | |
| 5 | ||
| 6 | selunit() | |
| 7 | { | |
| 8 | char fnam[20], s[50]; | |
| 9 | static char dobuff[50]; | |
| 10 | char posslev[20][20]; | |
| 11 | int diff[20], i, k, m, n, best, alts; | |
| 12 | FILE *f; | |
| 13 | char zb[200]; | |
| 14 | static char saved[20]; | |
| 15 | ||
| 16 | while (ask) { | |
| 17 | printf("What lesson? "); | |
| 18 | fflush(stdout); | |
| 19 | gets(dobuff); | |
| 20 | if (strcmp(dobuff, "bye") == 0) | |
| 21 | wrapup(0); | |
| 22 | level = todo = dobuff; | |
| 23 | sprintf(s, "../../%s/L%s", sname, dobuff); | |
| 24 | if (access(s, 04) == 0) | |
| 25 | return; | |
| 26 | printf("no such lesson\n"); | |
| 27 | } | |
| 28 | alts = 0; | |
| 29 | retry: | |
| 30 | f=scrin; | |
| 31 | if (f==NULL) { | |
| 32 | sprintf(fnam, "../../%s/L%s", sname, level); | |
| 33 | f = fopen(fnam, "r"); | |
| 34 | if (f==NULL) { | |
| 35 | fprintf(stderr, "No script for lesson %s.\n", level); | |
| 36 | wrapup(1); | |
| 37 | } | |
| 38 | while (fgets(zb, 200, f)) { | |
| 39 | trim(zb); | |
| 40 | if (strcmp(zb, "#next")==0) | |
| 41 | break; | |
| 42 | } | |
| 43 | } | |
| 44 | if (feof(f)) { | |
| 45 | printf("Congratulations; you have finished this sequence.\n"); | |
| 46 | fflush(stdout); | |
| 47 | todo = 0; | |
| 48 | return; | |
| 49 | } | |
| 50 | for(i=0; fgets(s, 50, f); i++) { | |
| 51 | sscanf(s, "%s %d", posslev[i], &diff[i]); | |
| 52 | } | |
| 53 | best = -1; | |
| 54 | /* cycle through lessons from random start */ | |
| 55 | /* first try the current place, failing that back up to | |
| 56 | last place there are untried alternatives (but only one backup) */ | |
| 57 | n = grand()%i; | |
| 58 | for(k=0; k<i; k++) { | |
| 59 | m = (n+k)%i; | |
| 60 | if (already(posslev[m],0)) continue; | |
| 61 | if (best<0) best=m; | |
| 62 | /* real alternatives */ | |
| 63 | alts++; | |
| 64 | if (abs(diff[m]-speed) < abs(diff[best]-speed)) | |
| 65 | best=m; | |
| 66 | } | |
| 67 | if (best < 0 && nsave) { | |
| 68 | nsave--; | |
| 69 | strcpy(level, saved); | |
| 70 | goto retry; | |
| 71 | } | |
| 72 | if (best <0) { | |
| 73 | /* lessons exhausted or missing */ | |
| 74 | printf("Sorry, there are no alternative lessons at this stage.\n"); | |
| 75 | printf("See someone for help.\n"); | |
| 76 | fflush(stdout); | |
| 77 | todo = 0; | |
| 78 | return; | |
| 79 | } | |
| 80 | strcpy (dobuff, posslev[best]); | |
| 81 | if (alts>1) { | |
| 82 | nsave=1; | |
| 83 | strcpy (saved, level); | |
| 84 | } | |
| 85 | todo = dobuff; | |
| 86 | fclose(f); | |
| 87 | } | |
| 88 | ||
| 89 | abs(x) | |
| 90 | { | |
| 91 | return(x>=0? x: -x); | |
| 92 | } | |
| 93 | ||
| 94 | grand() | |
| 95 | { | |
| 96 | static int garbage; | |
| 97 | int a[2], b; | |
| 98 | ||
| 99 | time(a); | |
| 100 | b = a[1]+10*garbage++; | |
| 101 | return(b&077777); | |
| 102 | } |