From 266761708869250f17a931f803d0a8f934973682 Mon Sep 17 00:00:00 2001
From: Bruno Raoult <braoult@gmail.com>
Date: Wed, 13 Jan 2021 08:37:55 +0100
Subject: [PATCH] Day 16/Part 1: C version.

---
 day16/Makefile |   2 +-
 day16/OUTPUT   |  12 ++++
 day16/ex1-c.c  | 165 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 178 insertions(+), 1 deletion(-)
 create mode 100644 day16/OUTPUT
 create mode 100644 day16/ex1-c.c

diff --git a/day16/Makefile b/day16/Makefile
index a1d3261..211cf64 100644
--- a/day16/Makefile
+++ b/day16/Makefile
@@ -17,7 +17,7 @@ compile: ex1-c ex2-c
 
 ex1:
 	@$(TIME) ex1.bash < $(INPUT) 2>&1
-	@#$(TIME) ex1-c 2020 < $(INPUT) 2>&1
+	@$(TIME) ex1-c 2020 < $(INPUT) 2>&1
 
 ex2:
 	@$(TIME) ex2.bash < $(INPUT) 2>&1
diff --git a/day16/OUTPUT b/day16/OUTPUT
new file mode 100644
index 0000000..b78c96d
--- /dev/null
+++ b/day16/OUTPUT
@@ -0,0 +1,12 @@
+ex1.bash : res=21996
+	time: 0:00.19 real, 0.15 user, 0.04 sys
+	context-switch:	26+98, page-faults: 0+9522
+
+ex1-c : res=21996
+	time: 0:00.00 real, 0.00 user, 0.00 sys
+	context-switch:	0+1, page-faults: 0+75
+
+ex2.bash : res=650080463519
+	time: 0:06.63 real, 6.59 user, 0.04 sys
+	context-switch:	666+92, page-faults: 0+10157
+
diff --git a/day16/ex1-c.c b/day16/ex1-c.c
new file mode 100644
index 0000000..74d93dc
--- /dev/null
+++ b/day16/ex1-c.c
@@ -0,0 +1,165 @@
+/* ex1-c: Advent2020 game, day 16/game 1
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define AA "ABCD"
+#define LAA sizeof(AA)
+
+/* tickets ranges */
+struct srange {
+    char *name;
+    int s1, e1;
+    int s2, e2;
+};
+
+struct list {
+    int size;
+    int last;
+    struct srange *ranges;
+} list = {
+    0, 0, NULL
+};
+
+#define BLOCKSIZE	1024    /* number of elements for realloc() */
+
+int *myticket=NULL;
+int *curticket=NULL;            /* current ticket */
+int ticketsize=0;
+
+void print_ranges()
+{
+    unsigned i, n=list.last;
+    struct srange *p=list.ranges;
+
+    fprintf(stderr, "LIST: address=%p last=%u size=%u\n", list.ranges, n, list.size);
+    for (i=0; i<n; ++i, ++p)
+        printf("\t[%03u] %u-%u %u-%u [%s]\n", i, p->s1, p->e1, p->s2, p->e2, p->name);
+}
+
+struct srange *add_range(name, s1, e1, s2, e2)
+    char *name;
+    int s1, e1, s2, e2;
+{
+    struct srange *p;
+
+    if (list.last == list.size) {
+        list.ranges=realloc(list.ranges, sizeof(struct srange)*BLOCKSIZE);
+        list.size+=BLOCKSIZE;
+    }
+    p=list.ranges+list.last;
+    p->name=strdup(name);
+    p->s1=s1;
+    p->e1=e1;
+    p->s2=s2;
+    p->e2=e2;
+    list.last++;
+    return p;
+}
+
+void print_ticket(ticket)
+    int *ticket;
+{
+    int i;
+    for (i=0; i<ticketsize; ++i)
+        printf("\t%2d: %d\n", i, *(ticket+i));
+}
+
+int *parse_ticket(str)
+    char *str;
+{
+    int i;
+    char *p;
+
+    if (!curticket)
+        curticket=malloc(ticketsize * sizeof *myticket);
+    for (i=0, p=str; i<ticketsize; ++i, ++p)
+        curticket[i]=(int)strtol(p, &p, 10);
+    return curticket;
+}
+
+int *parse_myticket(str)
+    char *str;
+{
+    int i=0;
+    char *p;
+
+    ticketsize=1;
+    for (p=str; *p; p++)
+        if (*p==',')
+            ticketsize++;
+
+    myticket=malloc(ticketsize * sizeof *myticket);
+    for (p=str, i=0; i<ticketsize; ++i, ++p)
+        myticket[i]=(int)strtol(p, &p, 10);
+    return myticket;
+}
+
+int is_in_range(i, range)
+    int i;
+    struct srange *range;
+{
+    if ((i>=range->s1 && i<=range->e1) || (i>=range->s2 && i<=range->e2))
+        return 1;
+    else
+        return 0;
+}
+
+int ex1(ticket)
+    int *ticket;
+{
+    int i, r, res=0, found;
+
+    for (i=0; i<ticketsize; ++i) {
+        found=0;
+        for (r=0; r<list.last; ++r) {
+            if (is_in_range(*(ticket+i), list.ranges+r)) {
+                found=1;
+                break;
+            }
+        }
+        if (!found)
+            res+=ticket[i];
+    }
+    return res;
+}
+
+int main(ac, av)
+    int ac;
+    char **av;
+{
+    char line[1024], pname[80], *elabel;
+    int s1, e1, s2, e2, end=0, status=0, res=0;
+    int *ticket;
+
+    while (fgets(line, sizeof line, stdin)) {
+        if (*line=='\n')
+            continue;
+        if (*line >= '0' && *line <= '9') {
+            switch (status) {
+                case 1:
+                    ticket=parse_myticket(line);
+                    break;
+                case 2:
+                    ticket=parse_ticket(line);
+                    res += ex1(ticket);
+                    break;
+            }
+            continue;
+        }
+        if (elabel=strchr(line, ':')) {
+            if (*(elabel+1)=='\n') {
+                status++;
+                continue;
+            }
+            sscanf(line, "%[^:]: %d-%d or %d-%d %n",
+                   pname, &s1, &e1, &s2, &e2, &end);
+            add_range(pname, s1, e1, s2, e2);
+
+        }
+    }
+    printf("%s : res=%d\n", *av, res);
+    exit (0);
+}