diff --git a/Makefile b/Makefile
index ddc8340..9893d08 100644
--- a/Makefile
+++ b/Makefile
@@ -1,11 +1,15 @@
 SHELL := /bin/bash
-CFLAGS := -w -O3 -pg
-#CFLAGS := -w -g -pg -DDEBUG
+#CFLAGS := -w -O3 -pg -DDEBUG -DDEBUG_BEST
+CFLAGS := -w -O3 -DDEBUG -DDEBUG_BEST
+# specific DEBUG flags:
+#     timer:        -DDEBUG_TIMER
+#     best control: -DDEBUG_BEST
+
 #CFLAGS := -w -g -pg -DDEBUG
 TIME := \time -f "\ttime: %E real, %U user, %S sys\n\tcontext-switch:\t%c+%w, page-faults: %F+%R\n"
 export PATH := .:$(PATH)
 
-TARGETS=lceb tree oper stack eval best
+TARGETS=lceb tree oper stack eval best timer
 INCLUDES=lceb.h
 OBJS=$(TARGETS:=.o)
 
@@ -20,6 +24,8 @@ tree: tree.c
 	$(CC) $(CFLAGS) -DSTANDALONE -o $@ $?
 oper: oper.c
 	$(CC) $(CFLAGS) -DSTANDALONE -o $@ $?
+timer: timer.c
+	$(CC) $(CFLAGS) -DSTANDALONE -o $@ $?
 
 lceb.o tree.o oper.o eval.o stack.o best.o: lceb.h
 tree oper: lceb.h
diff --git a/best.c b/best.c
index f96bb72..8a6027f 100644
--- a/best.c
+++ b/best.c
@@ -13,19 +13,19 @@ static int bestops=MAXINT;
 
 static BEST bests[1024*10];        /* TODO: should be dynamic */
 static int nbests=0;
-static int sigint=0;
+int sigint_received=0;
 
 #define DIFF(a, b) ((a)>(b)?(a)-(b):(b)-(a))
 
 void stopall()
 {
     printf("SIGINT RECEIVED: aborting eval\n");
-    sigint=1;
+    sigint_received=1;
 }
 
 int stopped()
 {
-    return sigint;
+    return sigint_received;
 }
 
 void set_target(n)
@@ -45,17 +45,10 @@ int check_best(res, nops, node, values, ops)
     int diff, found=0, i=0;
 
     diff=DIFF(target, res);
-#   ifdef DEBUG1
+#   ifdef DEBUG_BEST1
     printf("check_best: res=%d diff=%d nops=%d\n", res, diff, nops);
 #   endif
     if (diff < bestdiff || (diff == bestdiff && nops < bestops)) {
-#       ifdef DEBUG
-        // printf("NEW BEST! res=%d diff=%d nops=%d\n", res, diff, nops);
-        printf("diff=%d nops=%d %d=", diff, nops, res);
-        print_node(node, TREE_TOP, 0, 4);
-        putchar('\n');
-        //printf("check_best: res=%d diff=%d nops=%d\n", res, diff, nops);
-#       endif
         //best=res;
         // clear old bests
         for (i=0; i<nbests; ++i)
@@ -65,20 +58,29 @@ int check_best(res, nops, node, values, ops)
         nbests=0;
         found=1;
         //return 1;
-    } else if (diff == bestdiff && nops == bestops) {
-#       ifdef DEBUG1
+    }/* else if (diff == bestdiff && nops == bestops) {
+#       ifdef DEBUG_BEST
         printf("NEW BEST SOLUTION (%d):  res=%d diff=%d nops=%d\n", nbests+1, res, diff, nops);
         print_node(node, TREE_TOP, 0, 0);
 #       endif
         found=2;
-    }
+        }*/
     if (found==1) {
+        set_timer(&(bests[nbests].timer));
         bests[nbests].res=res;
         bests[nbests].diff=diff;
         bests[nbests].nops=nops;
         bests[nbests].oper=ops;
         bests[nbests].root=dup_node(node);
         bests[nbests].values=values;
+#       ifdef DEBUG_BEST
+        // printf("NEW BEST! res=%d diff=%d nops=%d\n", res, diff, nops);
+        printf("%.5f: diff=%d nops=%d %d=", get_timer(bests[nbests].timer),
+               diff, nops, res);
+        print_node(node, TREE_TOP, 0, 4);
+        putchar('\n');
+        //printf("check_best: res=%d diff=%d nops=%d\n", res, diff, nops);
+#       endif
         nbests++;
         return diff;
     }
@@ -114,10 +116,10 @@ void print_best(node, values, pops, depth)
 void print_bests()
 {
     int i;
-    printf("BESTS: diff=%d solutions=%d nops=%d\n", bestdiff, nbests, bestops);
+    printf("BEST SOLUTION: diff=%d ops=%d\n", bestdiff, bestops);
     for (i=0; i<nbests; ++i) {
         //print_best(bests[i].root, bests[i].values, bests[i].oper, 0);
-        printf("%3d: %d = ", i, bests[i].res);
+        printf("%.5f secs: %5d = ", get_timer(bests[i].timer), bests[i].res);
         print_node(bests[i].root, TREE_TOP, 0, 4);
         putchar('\n');
         //printf("%3d: %d = ", i, bests[i].res);
diff --git a/eval.c b/eval.c
index baa6208..e3a7ec6 100644
--- a/eval.c
+++ b/eval.c
@@ -2,6 +2,9 @@
 #include "lceb.h"
 
 
+static int nodes_calc;          /* total nodes evaluated */
+static int leaves_calc;         /* total leaves evaluated */
+
 int eval_node(node, depth, pvals, pops, ncalcs)
     NODE *node;
     int depth;
@@ -11,8 +14,8 @@ int eval_node(node, depth, pvals, pops, ncalcs)
 {
     static int *vals, *val_zero;
     static char *ops, *ops_zero;
-    static int totcalc;
     static *node_zero;
+    static int totcalc;
     int val1, val2, op, res=-1, i, lcalcs, rcalcs;
 
     if (depth == 0) {
@@ -34,12 +37,14 @@ int eval_node(node, depth, pvals, pops, ncalcs)
     }
 #   endif
     if (node->type == TREE_LEAF) {
+        leaves_calc++;
         node->val=*vals;
         res=*vals;
         vals++;
         *ncalcs=0;
         //printf("leaf=%d\n", res);
     } else {
+        nodes_calc++;
         op=*ops;
         node->op=*ops;
         ops++;
@@ -80,7 +85,7 @@ int eval_node(node, depth, pvals, pops, ncalcs)
         if (!check_best(res, *ncalcs, node, val_zero, ops_zero))
             res=-1;
     }
-    if (stopped()) {
+    if (sigint_received) {
         print_bests();
         exit(1);
     }
@@ -91,3 +96,12 @@ int eval_node(node, depth, pvals, pops, ncalcs)
 #   endif
     return res;
 }
+
+int get_totnodes()
+{
+    return nodes_calc;
+}
+int get_totleaves()
+{
+    return leaves_calc;
+}
diff --git a/lceb.c b/lceb.c
index d78d449..c8c1b87 100644
--- a/lceb.c
+++ b/lceb.c
@@ -12,6 +12,7 @@
 #include <stdarg.h>
 #include <malloc.h>
 #include <string.h>
+#include <locale.h>
 #include "lceb.h"
 
 int main(ac, av)
@@ -20,19 +21,20 @@ int main(ac, av)
 {
     unsigned target;
     STACK inputstack, *stack;
-    int i, j, k, stacksize, val, res;
-    //char *ops="+-*/", *opscomb;
-    //int len_ops=strlen(ops), ncombs, nops;
+    int i, j, k, stacksize, val;
     int ncombs, nstacks, ntrees, nops;
     TREE *tree;
     int intarray[1024];
     int eval;
     char *comb;
+    struct timespec end;
 
+    setlocale(LC_ALL, "");                        /* to use "%'d" in printf */
     if (ac < 4 || ac > 2+MAXINPUT) {
         fprintf(stderr, "usage: %s target n1 n2 [...n%d]\n", *av, MAXINPUT);
         exit(1);
     }
+    start_timer();
     target=atoi(av[1]);
     stacksize=2*(ac-2)-1;
     nops=ac-2-1;
@@ -110,5 +112,8 @@ int main(ac, av)
     }
     printf("\n");
     print_bests();
+    set_timer(&end);
+    printf("Total time elapsed: %.5f secs, nodes/leaves evaluated:%'d/%'d\n",
+           get_timer(end), get_totnodes(), get_totleaves());
     exit(0);
 }
diff --git a/lceb.h b/lceb.h
index d51471f..7421cfe 100644
--- a/lceb.h
+++ b/lceb.h
@@ -1,3 +1,4 @@
+#include <time.h>
 
 #define MAXINPUT        6                         /* max numbers as input */
 #define ALLOCSIZE       1024                      /* # of elements to alloc when needed */
@@ -55,6 +56,7 @@ typedef struct best {
     char *oper;
     NODE *root;
     int *values;
+    struct timespec timer;
 } BEST;
 
 /* tree.c */
@@ -103,6 +105,8 @@ extern char *nth_comb(int n);
 //extern int eval_stack(STACK *stack);
 /* tree version */
 extern int eval_node(NODE *node, int depth, int *pvals, char *pops, int *ncalcs);
+extern int get_totnodes();
+extern int get_totleaves();
 
 /* best.c */
 extern int stopped();
@@ -110,3 +114,9 @@ extern void set_target (int n);
 extern int check_best(int res, int nops, NODE *node, int *values, char *ops);
 extern void print_best(NODE *node, int *values, char *pops, int depth);
 extern void print_bests();
+
+/* timer.c */
+extern int sigint_received;
+extern void start_timer();
+extern void set_timer(struct timespec *timer);
+extern double get_timer(struct timespec timer);
diff --git a/timer.c b/timer.c
new file mode 100644
index 0000000..6a931f7
--- /dev/null
+++ b/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