Added timer for bests solutions

timer.c

@@ -0,0 +1,62 @@
+#include <stdio.h>
+#include <time.h>
+
+#define NANOSEC    1000000000.0
+#define MILLISEC   1000
+
+static  struct timespec start;
+
+void start_timer()
+{
+    printf("timer started...\n");
+    clock_gettime(CLOCK_MONOTONIC, &start);
+#   ifdef DEBUG_TIMER
+    printf("sec=%d nsec=%d\n", start.tv_sec, start.tv_nsec);
+#   endif
+}
+
+void set_timer(timer)
+    struct timespec *timer;
+{
+    clock_gettime(CLOCK_MONOTONIC, timer);
+#   ifdef DEBUG_TIMER
+    printf("timer: sec=%d nsec=%d orig: sec=%d nsec=%d\n",
+           timer->tv_sec, timer->tv_nsec, start.tv_sec, start.tv_nsec);
+#   endif
+}
+
+double get_timer(timer)
+    struct timespec timer;
+{
+    double diff;
+    diff=(timer.tv_sec - start.tv_sec) + (timer.tv_nsec - start.tv_nsec) / NANOSEC;
+#   ifdef DEBUG_TIMER
+    printf("timer sec: %.5f\n", diff);
+#   endif
+    return diff;
+}
+
+#ifdef STANDALONE
+main(ac, av)
+    int ac;
+    char **av;
+{
+    int delay;
+    struct timespec end, tsdelay;
+
+    if (ac != 2) {
+        fprintf(stderr, "usage: %s msecs\n", *av);
+        exit (1);
+    }
+    delay=atoi(*(av+1));
+    start_timer();
+    tsdelay.tv_sec=delay/MILLISEC;
+    tsdelay.tv_nsec=delay%MILLISEC;
+    printf("delay %d=%d:%d\n", delay, tsdelay.tv_sec, tsdelay.tv_nsec);
+    nanosleep(&tsdelay, NULL);
+    set_timer(&end);
+    printf("Time elapsed: %.5f seconds\n", get_timer(end));
+
+    return 0;
+}
+#endif