[이분탐색] 11월 8일

10_이분탐색/10815.cpp

@@ -0,0 +1,42 @@
+//10_이분탐색 필수1: 10815
+
+#include <iostream>
+#include <algorithm>
+
+using namespace std;
+
+int n, m;
+int arr[500000];
+
+int main() 
+{
+    ios::sync_with_stdio(false);
+    cin.tie(NULL);
+
+    cin >> n;
+
+    for (int i = 0; i < n; i++) {
+        cin >> arr[i];
+    }
+
+    // 숫자 카드 오름차순 정렬
+    sort(arr, arr + n);
+
+    cin >> m;
+
+    for (int i = 0; i < m; i++) 
+    {
+        int num;
+        cin >> num;
+
+        // 이분 탐색: 해당 숫자가 있는 경우
+        if (binary_search(arr, arr + n, num)) 
+        {
+            cout << "1 ";
+        } else {
+            cout << "0 ";
+        }
+    }
+
+    return 0;
+}

10_이분탐색/14500.cpp

@@ -0,0 +1,87 @@
+//10_이분탐색 필수2: 14500
+
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+int n, m, ans;
+vector<vector<int>> map;
+vector<vector<bool>> visit;
+vector<int> dy = {-1, 1, 0, 0};
+vector<int> dx = {0, 0, -1, 1};
+
+void dfs(int y, int x, int cnt, int sum, vector<vector<bool>>& visit) 
+{
+    if (cnt >= 4) 
+    {
+        ans = max(ans, sum);
+        return;
+    }
+
+    for (int k = 0; k < 4; k++) 
+    {
+        int ny = y + dy[k];
+        int nx = x + dx[k];
+
+        if (ny < 0 || nx < 0 || ny >= n || nx >= m || visit[ny][nx]) {
+            continue;
+        }
+
+        visit[ny][nx] = true;
+        dfs(ny, nx, cnt + 1, sum + map[ny][nx], visit);
+        visit[ny][nx] = false;
+    }
+}
+
+void check(int y, int x) 
+{
+    if (y < n - 2 && x < m - 1){
+        ans = max(ans, map[y][x] + map[y + 1][x] + map[y + 2][x] + map[y + 1][x + 1]);
+    }
+
+    if (y < n - 2 && x > 0){
+        ans = max(ans, map[y][x] + map[y + 1][x] + map[y + 2][x] + map[y + 1][x - 1]);
+    }
+
+    if (y < n - 1 && x < m - 2){
+        ans = max(ans, map[y][x] + map[y][x + 1] + map[y][x + 2] + map[y + 1][x + 1]);
+    }
+
+    if (y > 0 && x < m - 2){
+        ans = max(ans, map[y][x] + map[y][x + 1] + map[y][x + 2] + map[y - 1][x + 1]);
+    }
+}
+
+int main() 
+{
+    ios::sync_with_stdio(false);
+    cin.tie(NULL);
+
+    cin >> n >> m;
+    map.assign(n, vector<int>(m));
+    visit.assign(n, vector<bool>(m, false));
+
+    for (int i = 0; i < n; i++) 
+    {
+        for (int j = 0; j < m; j++) {
+            cin >> map[i][j];
+        }
+    }
+
+    for (int i = 0; i < n; i++) 
+    {
+        for (int j = 0; j < m; j++) 
+        {
+            visit[i][j] = true;
+            dfs(i, j, 1, map[i][j], visit);
+
+            visit[i][j] = false;
+            check(i, j);
+        }
+    }
+
+    cout << ans << "\n";
+
+    return 0;
+}

10_이분탐색/16401.cpp

@@ -0,0 +1,53 @@
+//10_이분탐색 필수3: 16401
+
+#include <iostream>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+int m, n, result;
+vector<int> arr;
+
+void bs(int s, int e) 
+{
+    if (s > e)
+        return;
+    int mid = (s + e) / 2;
+    int cnt = 0;
+
+    for (int i = 0; i < n; i++)
+        cnt += arr[i] / mid;
+
+    if (cnt >= m) 
+    {
+        if (result < mid){
+            result = mid;
+        }  
+        bs(mid + 1, e);
+    } 
+    else {
+        bs(s, mid - 1);
+    }
+}
+
+int main() 
+{
+    ios::sync_with_stdio(false);
+    cin.tie(NULL);
+
+    cin >> m >> n;
+    arr.resize(n);
+
+    for (int i = 0; i < n; i++){
+        cin >> arr[i];
+    }
+
+    sort(arr.begin(), arr.end());
+
+    bs(1, arr[n - 1]);
+
+    cout << result << "\n";
+
+    return 0;
+}

10_이분탐색/2343.cpp

@@ -0,0 +1,50 @@
+//10_이분탐색 도전1: 2343
+
+#include <iostream>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+int main() 
+{
+    int n, m;
+    cin >> n >> m;
+
+    vector<int> lengths(n);
+
+    for (int i = 0; i < n; i++) {
+        cin >> lengths[i];
+    }
+
+    int left = *max_element(lengths.begin(), lengths.end());
+    int right = 10000 * n; // 최대 블루레이 크기
+
+    while (left < right) 
+    {
+        int mid = (left + right) / 2;
+        int count = 1; // 블루레이 개수
+        int sum = 0; // 현재 녹화된 길이
+
+        for (int i = 0; i < n; i++) 
+        {
+            if (sum + lengths[i] > mid) 
+            {
+                count++;
+                sum = 0;
+            }
+            sum += lengths[i];
+        }
+
+        if (count <= m) {
+            right = mid;
+        } 
+        else {
+            left = mid + 1;
+        }
+    }
+
+    cout << left << "\n";
+
+    return 0;
+}

10_이분탐색/3079.cpp

@@ -0,0 +1,58 @@
+//10_이분탐색 도전2: 3079
+
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+long long MIN_TIME = 1;
+long long MAX_TIME = 1000000000LL * 1000000000LL;
+
+bool checkInTime(vector<int>& input, int n, int m, long long time) 
+{
+    long long peopleCnt = 0;
+    for (int i = 0; i < n; i++) 
+    {
+        peopleCnt += (time / input[i]);
+        if (peopleCnt >= m) {
+            return true;
+        }
+    }
+    return false;
+}
+
+long long binarySearch(vector<int>& input, int n, int m) 
+{
+    long long result = MAX_TIME;
+    long long start = MIN_TIME;
+    long long end = MAX_TIME;
+
+    while (start <= end) {
+        long long mid = (start + end) / 2;
+        if (checkInTime(input, n, m, mid)) 
+        {
+            end = mid - 1;
+            result = mid;
+        } 
+        else {
+            start = mid + 1;
+        }
+    }
+    return result;
+}
+
+int main() 
+{
+    int n, m;
+    cin >> n >> m;
+    vector<int> input(n);
+
+    for (int i = 0; i < n; i++) {
+        cin >> input[i];
+    }
+
+    long long answer = binarySearch(input, n, m);
+    cout << answer << ""\n;
+
+    return 0;
+}