diff --git a/BOJ/26-2-W2/BOJ10815/mindidii.cpp b/BOJ/26-2-W2/BOJ10815/mindidii.cpp
new file mode 100644
index 0000000..22aefb7
--- /dev/null
+++ b/BOJ/26-2-W2/BOJ10815/mindidii.cpp
@@ -0,0 +1,36 @@
+#include <iostream>
+#include <string>
+#include <vector>
+#include <queue>
+
+using namespace std;
+
+int nums[20000002]; // 지역변수로 사용하면 stack 영역에 저장하기 때문에 값이 터짐
+
+int main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+
+    int N;
+    cin >> N;
+    
+    int a;
+    for(int i=0; i<N; i++)
+    {
+        cin >> a;
+        nums[a + 10000000] = 1;
+    }
+
+    int M;
+    cin >> M;
+    int b;
+    for(int i=0; i<M; i++)
+    {
+        cin >> b;
+        if(nums[b + 10000000] == 1) cout << 1 <<' ';
+        else cout << 0 << ' ';
+    }
+
+    return 0;
+}
\ No newline at end of file
diff --git a/BOJ/26-2-W2/BOJ11053/mindidii.cpp b/BOJ/26-2-W2/BOJ11053/mindidii.cpp
new file mode 100644
index 0000000..ade77a9
--- /dev/null
+++ b/BOJ/26-2-W2/BOJ11053/mindidii.cpp
@@ -0,0 +1,38 @@
+#include <iostream>
+#include <string>
+#include <vector>
+#include <queue>
+
+using namespace std;
+
+int main()
+{
+
+    // 수열 A가 주어졌을 때 가장 긴 증가하는 수열 
+    int N;
+    cin >> N;
+    vector<int>nums(N);
+    vector<int>dp(N, 1);
+    for(int i=0; i<N; i++)
+    {
+        cin >> nums[i];
+    }
+
+    // dp테이블에 현재의 값보다 작은 개수를 count 해서 테이블을 체우기 
+    int result = 0;
+    for(int i=0; i<N; i++)
+    {
+        for(int j=0; j<i; j++)
+        {
+            if(nums[j] < nums[i])
+            {
+                dp[i] = max(dp[i], dp[j]+1);
+            }
+        }
+        result = max(result, dp[i]);
+    }
+
+    cout << result << '\n';
+
+    return 0;
+}
\ No newline at end of file
diff --git a/BOJ/26-2-W2/BOJ11399/mindidii.cpp b/BOJ/26-2-W2/BOJ11399/mindidii.cpp
new file mode 100644
index 0000000..a43b138
--- /dev/null
+++ b/BOJ/26-2-W2/BOJ11399/mindidii.cpp
@@ -0,0 +1,41 @@
+#include <iostream>
+#include <string>
+#include <vector>
+#include <queue>
+#include <algorithm>
+
+using namespace std;
+
+vector<int> line;
+
+int main()
+{
+    
+    int N;
+    cin >> N;
+    line.assign(N, 0);
+
+    for(int i=0; i<N; i++)
+    {
+        cin >> line[i];
+    }
+
+    sort(line.begin(), line.end());
+
+    vector<int>prefix(N);
+    prefix[0] = line[0];
+    for(int i=1; i<N; i++)
+    {
+        prefix[i] = prefix[i-1] + line[i];
+    }
+
+    int sum = 0;
+    for(int i=0; i<N; i++)
+    {
+        sum += prefix[i];
+    }
+
+    cout << sum << '\n';
+
+    return 0;
+}
\ No newline at end of file
diff --git a/BOJ/26-2-W2/BOJ18870/mindidii.cpp b/BOJ/26-2-W2/BOJ18870/mindidii.cpp
new file mode 100644
index 0000000..b9b21f2
--- /dev/null
+++ b/BOJ/26-2-W2/BOJ18870/mindidii.cpp
@@ -0,0 +1,38 @@
+#include <iostream>
+#include <string>
+#include <vector>
+#include <queue>
+#include <algorithm>
+#include <set>
+
+using namespace std;
+
+int main()
+{
+    int N;
+    cin >> N;
+
+    // 압축을 해야하는 수보다 작은 수의 개수로 압축
+    vector<int>coordinate(N);
+    for(int i=0; i<N; i++)
+    {
+        cin >> coordinate[i];
+    }
+
+    vector<int>ordered(N);
+    copy(coordinate.begin(), coordinate.end(), ordered.begin());
+    sort(ordered.begin(), ordered.end());
+
+    ordered.erase(unique(ordered.begin(), ordered.end()),ordered.end());
+
+    
+    for(int c:coordinate)
+    {
+        auto it = lower_bound(ordered.begin(),ordered.end(), c);
+        int count = distance(ordered.begin(), it);
+        cout << count << " ";
+    }
+    
+
+    return 0;
+}
\ No newline at end of file
diff --git a/BOJ/26-2-W2/BOJ5567/mindidii.cpp b/BOJ/26-2-W2/BOJ5567/mindidii.cpp
new file mode 100644
index 0000000..ff16cfc
--- /dev/null
+++ b/BOJ/26-2-W2/BOJ5567/mindidii.cpp
@@ -0,0 +1,70 @@
+    #include <iostream>
+    #include <string>
+    #include <vector>
+    #include <queue>
+
+    using namespace std;
+
+    int n, m;
+    vector<vector<int>>friends;
+    int visit[501];
+
+    void bfs(int start)
+    {
+        queue<int>q;
+        q.push(start);
+        visit[1] = 0;
+
+        while (!q.empty())
+        {
+            int curr = q.front();
+            q.pop();
+
+            for(int i=0; i<friends[curr].size(); i++)
+            {
+                int nxt = friends[curr][i];
+                if(visit[nxt] == -1)
+                {
+                    visit[nxt] = visit[curr] + 1; 
+                    q.push(nxt);
+                }
+            }
+        }
+        
+
+
+    }
+
+    int main()
+    {
+        cin >> n >> m;
+        friends.assign(n + 1, vector<int>());
+        fill(visit, visit+501, -1);
+        int check = false;
+        for(int i=0; i<m; i++)
+        {
+            int a, b;
+            cin >> a >> b;
+            friends[a].push_back(b);
+            friends[b].push_back(a);
+            if( a == 1 || b == 1) check = true;
+        }
+        
+        int cnt = 0;
+        if(!check)
+        { 
+            cout << 0 << '\n';
+            
+        }
+        else {
+            bfs(1); 
+            for(int i=0; i<n+2; i++)
+            {
+                if(visit[i] == 1 || visit[i] == 2) cnt++;
+            }
+            cout << cnt << '\n';
+        }
+
+        return 0;
+
+    }
\ No newline at end of file