advent2024

commit 0ec0bb8327ec020333db58355dc500d3dd8c4b26
parent 328ed172dcc9451f8ab3bb440f2374666af52432
Author: bsandro <email@bsandro.tech>
Date:   Thu, 26 Dec 2024 23:24:04 +0200

Day 13 p1

Diffstat:
M
day13/Makefile
 | 
12
+++++++++---
M
day13/main.cpp
 | 
21
++++++++++-----------

2 files changed, 19 insertions(+), 14 deletions(-)
diff --git a/day13/Makefile b/day13/Makefile
@@ -1,8 +1,14 @@
-NAME=$(shell basename ${PWD})
-SRC=$(wildcard *.cpp)
+NAME:=$(shell basename ${PWD})
+UNAME_S:=$(shell uname -s)
+SRC:=$(wildcard *.cpp)
 DEPS:=$(wildcard *.hpp)
 OBJ:=$(SRC:.cpp=.o)
-CXXFLAGS=-O2 -std=c++23 -Werror -Wall -Wextra -I. -I../include
+CXXSTD:="c++23"
+ifeq (${UNAME_S},OpenBSD)
+CXXSTD="c++2b"
+endif
+$(info advent of code on ${UNAME_S})
+CXXFLAGS=-O2 -std=${CXXSTD} -Werror -Wall -Wextra -I. -I../include
 LDFLAGS=-lstdc++
 
 all: $(NAME)
diff --git a/day13/main.cpp b/day13/main.cpp
@@ -65,28 +65,27 @@ T read_file(const std::string &path) {
     return buf;
 }
 
-void simulate(const Machine &m, int pA, int pB, std::vector<int> &out) {
-    if (pA>100||pB>100) return;
+bool simulate(const Machine &m, int pA, int pB, std::vector<int> &out) {
     int curX = m.btnA.x*pA + m.btnB.x*pB;
     int curY = m.btnA.y*pA + m.btnB.y*pB;
-    //std::printf("pA=%d, pB=%d, curX=%d, curY=%d\n", pA, pB, curX, curY);
-    if (curX>m.prize.x||curY>m.prize.y) return;
-    if (m.btnA.x*pA==m.prize.x&&m.btnB.y*pB==m.prize.y) {
+    if (curX>m.prize.x||curY>m.prize.y) return false;
+    if (curX==m.prize.x&&curY==m.prize.y) {
         out.push_back(pA*3+pB);
-    } else {
-        simulate(m, ++pA, pB, out);
-        simulate(m, pA, ++pB, out);
     }
+    return true;
 }
 
 int64_t part1(Data &input [[ maybe_unused ]]) {
     int64_t res = 0;
     for (auto &m:input) {
-        m.print();
         std::vector<int> runs;
-        simulate(m, 0, 0, runs);
+        for (int a=0;a<100;a++) {
+            for (int b=0;b<100;b++) {
+                if (!simulate(m, a, b, runs)) break;
+            }
+        }
         std::sort(runs.begin(), runs.end());
-        std::printf("%ld successful results\n", runs.size());
+        if (!runs.empty()) res += runs.back();
     }
 
     return res;