백준_문제풀이

Author: CHOOSLA

2025-09-02/추창우/백준_사전.cpp

@@ -0,0 +1,46 @@
+#include <cstring>
+#include <iostream>
+
+using namespace std;
+
+long long MAX = 1000000000;
+long long bino[201]
+              [201]; // 경우의 수가 기하 급수적으로 늘어나기 때문에 long long
+int n, m;
+long long k;
+
+void combi() {
+  for (int c = 0; c < 201; c++) {
+    bino[c][0] = bino[c][c] = 1;
+    for (int r = 1; r < c; r++) {
+      bino[c][r] = min(MAX, bino[c - 1][r - 1] + bino[c - 1][r]);
+    }
+  }
+}
+
+string dictionary(int n, int m, long long k) {
+  if (n == 0) {
+    return string(m, 'z');
+  }
+  if (m == 0)
+    return string(n, 'a');
+
+  if (k <= bino[n + m - 1][n - 1]) {
+    return "a" + dictionary(n - 1, m, k);
+  }
+  return "z" + dictionary(n, m - 1, k - bino[n + m - 1][n - 1]);
+}
+
+int main(void) {
+  memset(bino, 0, sizeof(bino));
+  cin >> n >> m >> k;
+
+  combi();
+  if (bino[n + m][n] < k) {
+    cout << -1;
+  } else {
+    cout << dictionary(n, m, k);
+  }
+
+  return 0;
+}

2025-09-02/추창우/백준_색종이_붙이기.cpp

@@ -0,0 +1,74 @@
+#include <iostream>
+#include <vector>
+using namespace std;
+
+const int N = 10;
+const int INF = 987654321;
+
+int board[N][N];
+vector<int> stock(6, 5);
+int bestAns = INF;
+
+bool canPlace(int y, int x, int k) {
+  if (y + k > N || x + k > N)
+    return false;
+  for (int i = 0; i < k; ++i)
+    for (int j = 0; j < k; ++j)
+      if (board[y + i][x + j] == 0)
+        return false;
+  return true;
+}
+
+void fillSquare(int y, int x, int k, int val) {
+  for (int i = 0; i < k; ++i)
+    for (int j = 0; j < k; ++j)
+      board[y + i][x + j] = val;
+}
+
+bool findNextOne(int &y, int &x) {
+  for (int i = 0; i < N; ++i)
+    for (int j = 0; j < N; ++j)
+      if (board[i][j] == 1) {
+        y = i;
+        x = j;
+        return true;
+      }
+  return false;
+}
+
+void dfs(int used) {
+  if (used >= bestAns)
+    return;
+
+  int y, x;
+  if (!findNextOne(y, x)) {
+    bestAns = min(bestAns, used);
+    return;
+  }
+
+  for (int k = 5; k >= 1; --k) {
+    if (stock[k] == 0)
+      continue;
+    if (!canPlace(y, x, k))
+      continue;
+    fillSquare(y, x, k, 0);
+    stock[k]--;
+    dfs(used + 1);
+    stock[k]++;
+    fillSquare(y, x, k, 1);
+  }
+}
+
+int main() {
+  ios::sync_with_stdio(false);
+  cin.tie(nullptr);
+
+  for (int i = 0; i < N; ++i)
+    for (int j = 0; j < N; ++j)
+      cin >> board[i][j];
+
+  dfs(0);
+
+  cout << (bestAns == INF ? -1 : bestAns) << '\n';
+  return 0;
+}