added timer for maxed calculation time.

lceb.c

@@ -20,6 +20,7 @@
 
 static char *cmd;
 static int treetype=TREE_CATALAN;
+static int maxmillisecs=0;
 extern int displaytimer, displayintermediate, displaytype, firstonly;
 int displaysummary=1;
 
@@ -42,7 +43,7 @@ void help()
 {
     usage();
     fprintf(stderr, "Countdown game solver.\n");
-    fprintf(stderr, "  -1: Stops immediately when one solution is found\n");
+    fprintf(stderr, "  -1: Show only one solution (immediate stop when exact solution found\n");
     fprintf(stderr, "  -c: Show solutions timer\n");
     fprintf(stderr, "  -d TYPE: Solutions display type. TYPE can be:\n");
     fprintf(stderr, "           r: RPN (default)\n");
@@ -54,6 +55,7 @@ void help()
     fprintf(stderr, "  -i: Show intermediate solutions\n");
     fprintf(stderr, "  -s: Do not show summary (time, nodes evaluated)\n");
     fprintf(stderr, "  -t: Use less trees (Wedderburn–Etherington instead of Catalan)\n");
+    fprintf(stderr, "  -T TIMER: Will stop after TIMER 1/10th seconds\n");
     fprintf(stderr, "  -h: This help\n");
 }
 
@@ -75,7 +77,7 @@ int main(ac, av)
     TREE *tree;
     char intarray[1024];
     char *comb;
-    char *options="1thcisd:";
+    char *options="1thcisd:T:";
     int option;
 #   ifdef DEBUG_MAINLOOP
     int eval;
@@ -124,6 +126,9 @@ int main(ac, av)
             case 's':
                 displaysummary=0;
                 break;
+            case 'T':
+                maxmillisecs=atoi(optarg)*100;
+                break;
             case 't':
                 treetype=TREE_WEDDERBURN;
                 break;
@@ -143,6 +148,8 @@ int main(ac, av)
     }
     setlocale(LC_ALL, "");                        /* to use "%'d" in printf */
     start_timer();
+    if (maxmillisecs)
+        set_alarm(maxmillisecs);
     target=atoi(av[optind]);
     stacksize=ac-optind-1;
     nops=stacksize-1;