add (programmers - level2 4문제): js 풀이

programmers/level2/가장 큰 정사각형 찾기.js

@@ -0,0 +1,32 @@
+function solution(board) {
+  const width = board[0].length;
+  const height = board.length;
+  let max = 0;
+
+  const dp = Array.from({ length: height }, (v, i) =>
+    Array.from({ length: width }, (v, i) => 0)
+  );
+
+  for (let i = 0; i < height; i++) {
+    dp[i][0] = board[i][0];
+  }
+  for (let i = 0; i < width; i++) {
+    dp[0][i] = board[0][i];
+  }
+
+  for (let i = 1; i < height; i++) {
+    for (let j = 1; j < width; j++) {
+      if (board[i][j] === 1) {
+        dp[i][j] = Math.min(dp[i - 1][j - 1], dp[i][j - 1], dp[i - 1][j]) + 1;
+      }
+    }
+  }
+
+  for (let i = 0; i < height; i++) {
+    for (let j = 0; j < width; j++) {
+      max = Math.max(max, dp[i][j]);
+    }
+  }
+
+  return max * max;
+}

programmers/level2/뒤에 있는 큰 수 찾기.js

@@ -0,0 +1,18 @@
+function solution(numbers) {
+  const answer = Array.from({ length: numbers.length }, (v, i) => -1);
+  const stack = [];
+
+  for (let i = 0; i < numbers.length; i++) {
+    while (stack) {
+      const top = stack.at(-1);
+      if (numbers[top] < numbers[i]) {
+        answer[top] = numbers[i];
+        stack.pop();
+      } else {
+        break;
+      }
+    }
+    stack.push(i);
+  }
+  return answer;
+}

programmers/level2/멀쩡한 사각형.js

@@ -0,0 +1,7 @@
+const getGCD = (num1, num2) => {
+  return num2 === 0 ? num1 : getGCD(num2, num1 % num2);
+};
+
+function solution(w, h) {
+  return w * h - (w + h - getGCD(w, h));
+}

programmers/level2/택배상자.js

@@ -0,0 +1,22 @@
+function solution(order) {
+  let answer = 0;
+  const belt = Array.from({ length: order.length }, (v, i) => order.length - i);
+  const stack = [];
+
+  for (let i = 0; i < order.length; i++) {
+    const current = order[i];
+
+    while (belt.at(-1) <= current) {
+      stack.push(belt.pop());
+    }
+
+    const stackTop = stack.at(-1);
+    if (stackTop === current) {
+      stack.pop();
+      answer++;
+    } else {
+      break;
+    }
+  }
+  return answer;
+}