Initial Commit - days 01-12

2020-12-21 14:58:15 +01:00
commit 11844d1904
131 changed files with 16060 additions and 0 deletions
--- a/day08/ex2-c.c
+++ b/day08/ex2-c.c
@@ -0,0 +1,184 @@
+/* ex1-c: Advent2020 game, day 8/game 1
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct instr {
+    struct instr *next;
+    int instr;
+    int val;
+    int visited;
+};
+
+struct program {
+    unsigned length;
+    unsigned total;
+    struct instr *prg;
+};
+
+#define BLOCKSIZE	1024    /* number of elements for realloc() */
+#define	NOP		0
+#define	ACC		1
+#define	JMP		2
+
+void print_instr(prg, step, cur)
+    struct program *prg;
+    int step;
+    int cur;
+{
+    struct instr *instr=prg->prg+step;
+    char *op="unknown";
+
+    switch (instr->instr) {
+        case NOP:
+            op="nop";
+            break;
+        case JMP:
+            op="jmp";
+            break;
+        case ACC:
+            op="acc";
+            break;
+    }
+    fprintf(stderr, "%03d: [%s][%4d] -> %4d\n", step, op, instr->val, cur);
+}
+
+void print_prg(prg)
+    struct program *prg;
+{
+    unsigned i, psize=prg->length;
+    struct instr *pinstr=prg->prg;
+
+    fprintf(stderr, "PROGRAM: address=%p pinstr=%p size=%d\n", prg, pinstr, psize);
+    for (i=0; i<psize; ++i)
+        print_instr(prg, i, 0);
+}
+
+void reset_prg(prg)
+    struct program *prg;
+{
+    unsigned i, psize=prg->length;
+    struct instr *pinstr=prg->prg;
+
+    for (i=0; i<psize; ++i)
+        pinstr[i].visited=0;
+}
+
+static struct program *add_line(prg, line)
+    struct program *prg;
+    char *line;
+{
+    char sinstr[80];
+    int val;
+    unsigned cur, total;
+    struct instr *pinstr;
+
+    if (!prg) {
+        prg=malloc(sizeof (struct program));
+        prg->prg=malloc(sizeof(struct instr)*BLOCKSIZE);
+
+        //fprintf(stderr, "alloc buf: prg=%p prog=%p\n", prg, prg->prg);
+        prg->length=0;
+        prg->total=BLOCKSIZE;
+    }
+    cur=prg->length;
+    total=prg->total;
+
+    if (cur == total) {
+        total+=BLOCKSIZE;
+        prg->total=total;
+        prg->prg=realloc(prg->prg, sizeof(struct instr)*total);
+        //fprintf(stderr, "realloc buf: cur=%d total=%d prog=%p\n", cur, total, prg->prg);
+    }
+    pinstr=prg->prg+cur;
+
+    sscanf(line, "%s %d", sinstr, &val);
+    pinstr->visited=0;
+    pinstr->val=val;
+    if (!strcmp(sinstr, "jmp"))
+        pinstr->instr=JMP;
+    else if (!strcmp(sinstr, "acc"))
+        pinstr->instr=ACC;
+    else pinstr->instr=NOP;
+    prg->length++;
+
+    return prg;
+}
+
+int run2(prg, ret)
+    struct program *prg;
+    int *ret;
+{
+    int cur=0, length=prg->length;
+    struct instr *instr=prg->prg;
+    int res=0;
+
+    reset_prg(prg);
+    //fprintf(stderr, "RUN: address=%p prg=%p size=%d\n", prg, instr, length);
+    //print_prg(prg);
+    while (cur>=0 && cur<length) {
+        instr=prg->prg+cur;
+        //print_instr(prg, cur, res);
+        if (instr->visited) {
+            return 1;
+        }
+        instr->visited=1;
+        switch (instr->instr) {
+            case NOP:
+                cur++;
+                break;
+            case JMP:
+                cur+=instr->val;
+                break;
+            case ACC:
+                res+=instr->val;
+                cur++;
+                break;
+        }
+    }
+    *ret=res;
+    return 0;
+}
+
+int main(ac, av)
+    char **av;
+{
+    char line[512];
+    struct program *prg=NULL;
+    struct instr *instr;
+    int res=0, cur=0, length=0;
+
+    while (fgets(line, sizeof line, stdin)) {
+        prg=add_line(prg, line);
+    }
+    instr=prg->prg;
+    length=prg->length;
+    if (run2(prg, &res)) {
+        do {
+            while (cur<length && instr[cur].instr == ACC)
+                cur++;
+            if (cur < length) {
+                int isav=instr[cur].instr;
+                switch (isav) {
+                    case NOP:
+                        instr[cur].instr=JMP;
+                        break;
+                    case JMP:
+                        instr[cur].instr=NOP;
+                        break;
+                }
+                if (!run2(prg, &res))
+                    break;
+                instr[cur].instr=isav;
+
+            } else
+                break;
+            cur++;
+        } while (cur>=0 && cur<length);
+    }
+    printf("%s : res=%d\n", *av, res);
+    exit(0);
+
+}