days 4, 5 and 6, not bad

d04/run.c

@@ -0,0 +1,25 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <openssl/md5.h>
+
+/**
+ compile with `tcc -lssl run.c`
+ run with `./a.out | grep -F ' 000000'`, then CTRL+C
+ */
+void main(int argc, char **argv) {
+	unsigned char digest[16];
+	char string[32];
+	MD5_CTX context;
+  for (int i=1;;i++) {
+		printf("%d ",i);
+		sprintf(string,"ckczppom%d",i);
+		MD5_Init(&context);
+		MD5_Update(&context, string, strlen(string));
+		MD5_Final(digest, &context);
+		for(int i = 0; i < 16; ++i) {
+	    printf("%02x", (unsigned int)digest[i]);
+		}
+		printf("\n");
+	}
+}