From b2afd231e730cd4b90babf787c68a3b53b8a60f8 Mon Sep 17 00:00:00 2001
From: sh0723 <pshpark12345@naver.com>
Date: Mon, 22 Jun 2026 12:32:37 +0900
Subject: [PATCH] =?UTF-8?q?17071=20:=20=EC=88=A8=EB=B0=94=EA=BC=AD?=
 =?UTF-8?q?=EC=A7=88=205=20solve?=
MIME-Version: 1.0
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---
 src/week3/BOJ17071/BOJ17071_V1.cpp | 48 ++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 src/week3/BOJ17071/BOJ17071_V1.cpp

diff --git a/src/week3/BOJ17071/BOJ17071_V1.cpp b/src/week3/BOJ17071/BOJ17071_V1.cpp
new file mode 100644
index 0000000..1842ad0
--- /dev/null
+++ b/src/week3/BOJ17071/BOJ17071_V1.cpp
@@ -0,0 +1,48 @@
+#include <bits/stdc++.h>
+using namespace std;
+int visited[2][500001];
+int bro, subin;
+int main() {
+
+    ios_base::sync_with_stdio(false);
+    cout.tie(NULL);
+    cin.tie(NULL);
+
+    cin >> subin >> bro;
+
+    if (subin == bro) {
+        cout << 0;
+        return 0;
+    }
+
+    queue<int> q;
+    q.push(subin);
+    visited[0][subin] = 1;
+    int t=0;
+    while(!q.empty()) {
+        int qsize = q.size();
+        int brother_pos = t*(t+1)/2 + bro;
+        if (brother_pos > 500000)
+            break;
+        if (visited[t%2][brother_pos]) {
+            cout << t;
+            return 0;
+        }
+        while(qsize--) {
+            int curr = q.front();
+            q.pop();
+
+            for (int next : {curr-1, curr+1, curr*2}) {
+                if (next < 0 || next > 500000) continue;
+                if (visited[(t+1)%2][next]) continue;
+                visited[(t+1)%2][next] = 1;
+                q.push(next);
+            }
+        }
+        t++;
+    }
+
+    cout << -1;
+
+    return 0;
+}
\ No newline at end of file