advent2015

commit f9bce4673dd2ad4de61dad9dc7243695b7cd8f40
parent 1cdcb262ac6836d10ba27344b28be3e614d077e9
Author: bsandro <email@bsandro.tech>
Date:   Mon,  2 Dec 2024 01:01:15 +0200

day 04 p1+p2

Diffstat:
A
day04/Makefile
 | 
28
++++++++++++++++++++++++++++
A
day04/main.cpp
 | 
43
+++++++++++++++++++++++++++++++++++++++++++

2 files changed, 71 insertions(+), 0 deletions(-)
diff --git a/day04/Makefile b/day04/Makefile
@@ -0,0 +1,28 @@
+NAME=$(shell basename ${PWD})
+SRC=$(wildcard *.cpp)
+DEPS:=$(wildcard *.hpp)
+OBJ:=$(SRC:.cpp=.o)
+CXXFLAGS=-O2 -std=c++17 -Werror -Wall -Wextra -I.
+LDFLAGS=-lstdc++ -lcrypto
+
+all: $(NAME)
+
+.PHONY: clean run
+
+clean:
+	rm -f $(OBJ) $(NAME)
+
+%.o : %.c $(DEPS)
+	@$(CC) $(CFLAGS) -c $< -o $@
+
+$(NAME): $(OBJ)
+	@$(CC) $(OBJ) -o $@ $(LDFLAGS)
+
+run: $(NAME)
+	@./$(NAME) yzbqklnj
+
+test1: $(NAME)
+	@./$(NAME) abcdef
+
+test2: $(NAME)
+	@./$(NAME) pqrstuv
diff --git a/day04/main.cpp b/day04/main.cpp
@@ -0,0 +1,43 @@
+#include <iostream>
+#include <filesystem>
+#include <fstream>
+#include <sstream>
+#include <vector>
+#include <cstring>
+#include <cstdio>
+#include <tuple>
+#include <algorithm>
+#include <openssl/md5.h>
+#include <openssl/evp.h>
+
+std::string md5(const std::string &str){
+    unsigned char hash[MD5_DIGEST_LENGTH];
+    EVP_Q_digest(NULL, "MD5", NULL, str.c_str(), str.size(), hash, NULL);
+    std::stringstream ss;
+    for(int i = 0; i < MD5_DIGEST_LENGTH; i++){
+        ss << std::hex << std::setw(2) << std::setfill('0') << static_cast<int>(hash[i]);
+    }
+    return ss.str();
+}
+
+int solve(const std::string input, const std::string prefix) {
+    for (int i=0; i<INT_MAX; ++i) {
+        if (md5(input+std::to_string(i)).compare(0, prefix.size(), prefix)==0) {
+            return i;
+        }
+    }
+    return 0;
+}
+
+int main(int argc, char **argv) {
+    if (argc<2) {
+        std::cerr << "No argument string provided" << std::endl;
+        return -1;
+    }
+    const std::string input = argv[1];
+    std::cout << "AoC 2015 day 04 " << input << std::endl;
+    std::cout << "part1: " << solve(input, "00000") << std::endl;
+    std::cout << "part2: " << solve(input, "000000") << std::endl;
+
+    return 0;
+}