From f2c57849af5cf566e8c97ca12226bfc229eab53e Mon Sep 17 00:00:00 2001
From: sh0723 <pshpark12345@naver.com>
Date: Fri, 22 May 2026 18:00:54 +0900
Subject: [PATCH] =?UTF-8?q?1940=20:=20=EC=A3=BC=EB=AA=BD=20solve=20v1,=20v?=
 =?UTF-8?q?2?=
MIME-Version: 1.0
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---
 src/week1/BOJ1940/BOJ1940_V1.cpp | 30 ++++++++++++++++++++++++++
 src/week1/BOJ1940/BOJ1940_V2.cpp | 36 ++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)
 create mode 100644 src/week1/BOJ1940/BOJ1940_V1.cpp
 create mode 100644 src/week1/BOJ1940/BOJ1940_V2.cpp

diff --git a/src/week1/BOJ1940/BOJ1940_V1.cpp b/src/week1/BOJ1940/BOJ1940_V1.cpp
new file mode 100644
index 0000000..bf7dbb9
--- /dev/null
+++ b/src/week1/BOJ1940/BOJ1940_V1.cpp
@@ -0,0 +1,30 @@
+#include <bits/stdc++.h>
+using namespace std;
+int main() {
+
+    int N;
+    cin >> N;
+
+    int n;
+    cin >> n;
+
+    vector<int> v;
+    for (int i=0; i<N; i++) {
+        int temp;
+        cin >> temp;
+        v.push_back(temp);
+    }
+
+    int cnt = 0;
+    for (int i=0; i<N; i++) {
+        for(int j=i+1; j<N; j++) {
+            if (v[i] + v[j] == n) {
+                cnt++;
+            }
+        }
+    }
+
+
+    cout << cnt << "\n";
+    return 0;
+}
\ No newline at end of file
diff --git a/src/week1/BOJ1940/BOJ1940_V2.cpp b/src/week1/BOJ1940/BOJ1940_V2.cpp
new file mode 100644
index 0000000..9a311f4
--- /dev/null
+++ b/src/week1/BOJ1940/BOJ1940_V2.cpp
@@ -0,0 +1,36 @@
+#include <bits/stdc++.h>
+using namespace std;
+vector<int> v;
+vector<int> choose;
+int cnt;
+int N;
+int n;
+void solve(int start){
+    if (choose.size() == 2) {
+        if (choose[0] + choose[1] == n)
+            cnt++;
+        return;
+    }
+
+    for (int i=start; i<N; i++) {
+        choose.push_back(v[i]);
+        solve(i+1);
+        choose.pop_back();
+    }
+}
+int main() {
+    cin >> N;
+
+    cin >> n;
+
+    for (int i=0; i<N; i++) {
+        int temp;
+        cin >> temp;
+        v.push_back(temp);
+    }
+
+    solve(0);
+
+    cout << cnt << "\n";
+    return 0;
+}