boj step 9 rework & aloha graph1(16174,2606,1520)

zeta_cpp/completed/1920.cpp

@@ -0,0 +1,49 @@
+#include <iostream>
+#include <algorithm>
+
+using namespace std;
+
+bool isExist(int x, int L[], int size) { // binsearch
+    int begin = 0;
+    int end = size - 1;
+    int mid;
+    int sep;
+    while (begin <= end) {
+        mid = (begin + end) / 2;
+        sep = L[mid];
+        if (x == sep) {
+            return true;
+        } else if (x < sep) {
+            end = mid - 1;
+        } else {
+            begin = mid + 1;
+        }
+    }
+    return false;
+}
+
+int main() {
+    int N, M;
+    ios::sync_with_stdio(0);
+    cin.tie(NULL);
+    cout.tie(NULL);
+    cin >> N;
+    int A[N];
+    for (int i = 0; i < N; i++) {
+        cin >> A[i];
+    }
+    sort(A, A + N);
+
+    cin >> M;
+    int x;
+    for (int i = 0; i < M; i++) {
+        cin >> x;
+        if (isExist(x, A, N)) {
+            cout << "1\n";
+        } else {
+            cout << "0\n";
+        }
+
+    }
+    return 0;
+}

zeta_cpp/completed/2501.cpp

@@ -0,0 +1,29 @@
+#include <iostream>
+#include <cmath>
+
+using namespace std;
+
+int main() {
+    int count = 1;
+    int N, K;
+
+    cin >> N >> K;
+    if(K == 1) {
+        cout << 1 << endl;
+        return 0;
+    }
+    for(int i=2;i<=N;i++) {
+        if (N%i == 0) {
+            count += 1;
+            if (count == K) {
+                cout << i << endl;
+                break;
+            }
+        }
+    }
+    if (K > count) {
+        cout << 0 << endl;
+    }
+
+    return 0;
+}

zeta_cpp/completed/9506.cpp

@@ -0,0 +1,45 @@
+#include <iostream>
+#include <vector>
+#include <numeric>
+#include <algorithm>
+
+using namespace std;
+
+vector<int> isPerfect(int N) {
+    vector<int> v;
+    for (int i = 1; i < N; i++) {
+        if (N % i == 0) {
+            v.push_back(i);
+        }
+    }
+
+    int result = accumulate(v.begin(), v.end(), 0);
+    if (result == N) {
+        return v;
+    } else {
+        return vector<int>();
+    }
+
+}
+
+int main() {
+    int input;
+    vector<int> out;
+    cin >> input;
+    while (input != -1) {
+
+        out = isPerfect(input);
+        if (out.size() > 0) {
+            cout << input << " = " << out[0];
+            for (int i = 1; i < out.size(); i++) {
+                cout << " + " << out[i];
+            }
+            cout << endl;
+        } else {
+            cout << input << " is NOT perfect." << endl;
+        }
+        cin >> input;
+    }
+
+    return 0;
+}