advent2015

commit 1cdcb262ac6836d10ba27344b28be3e614d077e9
parent ac27b7e2819f29118776896fed3f2535c4893f36
Author: bsandro <email@bsandro.tech>
Date:   Mon,  2 Dec 2024 00:08:43 +0200

day 03 p2

Diffstat:
M
day03/main.cpp
 | 
16
++++++++++++++--

1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/day03/main.cpp b/day03/main.cpp
@@ -38,8 +38,20 @@ int part1(Data &input) {
     return visited.size();
 }
 int part2(Data &input) {
-    (void)input;
-    return 0;
+    std::set<std::pair<int, int>> visited;
+    visited.insert(std::make_pair(0, 0));
+    std::pair<int,int> cur1{0, 0};
+    std::pair<int,int> cur2{0, 0};
+    for (int i=0; i<(int)input.size(); ++i) {
+        auto &cur = i%2==0?cur1:cur2;
+        char c = input[i];
+        if (c=='>') ++cur.first;
+        else if (c=='<') --cur.first;
+        else if (c=='^') ++cur.second;
+        else if (c=='v') --cur.second;
+        visited.insert(cur);
+    }
+    return visited.size();
 }
 
 int main(int argc, char **argv) {