advent-of-code

commit 48d2de6074473bc08bb44a1e16b5c1075c1bf7c7
parent eeaa0335d156f878e123eff64c983e835d254a2d
Author: aabacchus <ben@bvnf.space>
Date:   Fri,  4 Feb 2022 03:49:17 +0000

15.4

Diffstat:
A
2015/04/4.c
 | 
44
++++++++++++++++++++++++++++++++++++++++++++
A
2015/04/4.sh
 | 
17
+++++++++++++++++

2 files changed, 61 insertions(+), 0 deletions(-)
diff --git a/2015/04/4.c b/2015/04/4.c
@@ -0,0 +1,44 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <md5.h>
+
+int main(void) {
+    uint8_t input[] = {'b', 'g', 'v', 'y', 'z', 'd', 's', 'v', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+    const size_t input_len = 8;
+    const size_t input_len_m = 18;
+
+    MD5_CTX *m = malloc(sizeof(MD5_CTX));
+    if (m == NULL) {
+        perror("malloc");
+        return 1;
+    }
+
+    char *digest = NULL;
+
+    long j = 1;
+
+    while (1) {
+        printf("%ld\r", j);
+        int used = snprintf((char *)input + input_len, input_len_m - input_len, "%ld", j);
+
+        MD5Init(m);
+        MD5Update(m, input, input_len+used);
+        digest = MD5End(m, digest);
+
+        for (int i = 0; i < 6; i++) {
+            if (digest[i] != '0')
+                break;
+            if (i == 5)
+                goto end;
+        }
+        j++;
+    }
+end:
+    printf("%ld\n", j);
+    printf("%s\n", digest);
+    free(digest);
+    free(m);
+
+    return 0;
+}
diff --git a/2015/04/4.sh b/2015/04/4.sh
@@ -0,0 +1,17 @@
+#!/bin/sh -e
+
+input="bgvyzdsv"
+
+i=1038000
+
+while :; do
+    printf "\r%d" "$i"
+    case "$(printf "%s%d" "$input" "$i" | md5sum)" in
+        00000*)
+            echo;
+            break;
+        ;;
+    esac
+    i=$((i+1))
+done
+wait