diff --git a/src/sejinpark/Binary_Search/10815.cpp b/src/sejinpark/Binary_Search/10815.cpp
new file mode 100644
index 0000000..fb59f70
--- /dev/null
+++ b/src/sejinpark/Binary_Search/10815.cpp
@@ -0,0 +1,32 @@
+#include "bits/stdc++.h"
+using namespace std;
+int n, m;
+int cards[500001];
+int hCards[500001];
+int main(void){
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    cin >> n;
+    for (int i = 0; i < n; i++) {
+        int num;
+        cin >> num;
+        cards[i] = num;
+    }
+    cin >> m;
+    for (int i = 0; i < m; i++) {
+        int num;
+        cin >> num;
+        hCards[i] = num;
+    }
+    sort(cards, cards + n);
+    for (int i = 0; i < m; i++) {
+        if (binary_search(cards, cards + n, hCards[i])) {
+            hCards[i] = 1;
+            continue;
+        }
+        hCards[i] = 0;
+    }
+    for (int i = 0; i < m; i++) {
+        cout << hCards[i] << " ";
+    }
+}
\ No newline at end of file
diff --git a/src/sejinpark/Binary_Search/1822.cpp b/src/sejinpark/Binary_Search/1822.cpp
new file mode 100644
index 0000000..14c620b
--- /dev/null
+++ b/src/sejinpark/Binary_Search/1822.cpp
@@ -0,0 +1,36 @@
+#include "bits/stdc++.h"
+using namespace std;
+int a, b;
+int arrA[500001];
+int arrB[500001];
+int main(void){
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    cin >> a >> b;
+    for (int i = 0; i < a; i++) {
+        int num;
+        cin >> num;
+        arrA[i] = num;
+    }
+    for (int i = 0; i < b; i++) {
+        int num;
+        cin >> num;
+        arrB[i] = num;
+    }
+    sort(arrB, arrB + b);
+    vector<int> V;
+    for (int i = 0; i < a; i++) {
+        if (!binary_search(arrB, arrB + b, arrA[i])) {
+            V.push_back(arrA[i]);
+        }
+    }
+    if (V.empty()) {
+        cout << 0;
+        return 0;
+    }
+    sort(V.begin(), V.end());
+    cout << V.size() << "\n";
+    for (auto i: V) {
+        cout << i << " ";
+    }
+}
\ No newline at end of file
diff --git a/src/sejinpark/Sweeping/2170.cpp b/src/sejinpark/Sweeping/2170.cpp
new file mode 100644
index 0000000..fd0e261
--- /dev/null
+++ b/src/sejinpark/Sweeping/2170.cpp
@@ -0,0 +1,31 @@
+#include "bits/stdc++.h"
+using namespace std;
+int n;
+int main(void) {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    cin >> n;
+    vector<pair<int, int>> V;
+    for (int i = 0; i < n; i++) {
+        int x, y;
+        cin >> x >> y;
+        V.push_back({x, y});
+    }
+    sort(V.begin(), V.end());
+    int start = V[0].first;
+    int end = V[0].second;
+    int len = 0;
+    for (int i = 1; i < n; i++) {
+        int from = V[i].first;
+        int to = V[i].second;
+        if (from <= end) {
+            end = (to > end ? to : end);
+        } else {
+            len += end - start;
+            start = from;
+            end = to;
+        }
+    }
+    len += end - start;
+    cout << len;
+}
\ No newline at end of file
diff --git a/src/sejinpark/Sweeping/2836.cpp b/src/sejinpark/Sweeping/2836.cpp
new file mode 100644
index 0000000..8e24a8f
--- /dev/null
+++ b/src/sejinpark/Sweeping/2836.cpp
@@ -0,0 +1,37 @@
+#include "bits/stdc++.h"
+using namespace std;
+using ll = long long;
+int n, m;
+int main(void){
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    cin >> n >> m;
+    vector<pair<ll, ll>> V;
+    for (int i = 0; i < n; i++) {
+        ll a, b;
+        cin >> a >> b;
+        if(a > b) {
+            V.push_back({b,a});
+            continue;
+        }
+    }
+    sort(V.begin(), V.end());
+    ll start = V[0].first;
+    ll end = V[0].second;
+    ll len = 0;
+    ll ans = m;
+    for (int i = 1; i < V.size(); i++) {
+        auto from = V[i].first;
+        auto to = V[i].second;
+        if(from <= end) {
+            end = (to > end ? to : end);
+        } else {
+            len += end - start;
+            start = from;
+            end = to;
+        }
+    }
+    len += end - start;
+    ans += 2 * len;
+    cout << ans;
+}