week 06

Author: BaeKwangho

longest-increasing-subsequence/Baekwangho.ts

@@ -0,0 +1,86 @@
+/**
+(0,0) 에서 시작해서, 위 아래 끝값 및 왼쪽 오른쪽의 끝값을 갱신해가며
+현재 위치가 이보다 커질 경우 각각을 -1 하고 방향을 바꿔준다.
+ */
+function spiralOrder(matrix: number[][]): number[] {
+  let hmin = 0,
+    hmax = matrix[0].length - 1,
+    vmin = 0,
+    vmax = matrix.length - 1;
+  let x = 0,
+    y = 0;
+  const result = [];
+  let currentStep = [1, 0];
+
+  while (hmax >= hmin && vmax >= vmin) {
+    result.push(matrix[y][x]);
+
+    const next = applyCurrentStep(currentStep, x, y, hmin, hmax, vmin, vmax);
+    currentStep = next.nextStep;
+    x = next.x;
+    y = next.y;
+    hmin = next.hmin;
+    hmax = next.hmax;
+    vmin = next.vmin;
+    vmax = next.vmax;
+
+    // console.log(currentStep, x, y, hmin, hmax, vmin, vmax)
+  }
+  return result;
+}
+
+function applyCurrentStep(
+  currentStep: number[],
+  x: number,
+  y: number,
+  hmin: number,
+  hmax: number,
+  vmin: number,
+  vmax: number
+) {
+  let nextStep = currentStep;
+
+  switch (true) {
+    case currentStep[0] === 1 && currentStep[1] === 0: {
+      if (x >= hmax) {
+        nextStep = [0, 1];
+        y += 1;
+        vmin += 1;
+      } else {
+        x += 1;
+      }
+      break;
+    }
+    case currentStep[0] === 0 && currentStep[1] === 1: {
+      if (y >= vmax) {
+        nextStep = [-1, 0];
+        x -= 1;
+        hmax -= 1;
+      } else {
+        y += 1;
+      }
+      break;
+    }
+    case currentStep[0] === -1 && currentStep[1] === 0: {
+      if (hmin >= x) {
+        nextStep = [0, -1];
+        y -= 1;
+        vmax -= 1;
+      } else {
+        x -= 1;
+      }
+      break;
+    }
+    case currentStep[0] === 0 && currentStep[1] === -1: {
+      if (vmin >= y) {
+        nextStep = [1, 0];
+        x += 1;
+        hmin += 1;
+      } else {
+        y -= 1;
+      }
+      break;
+    }
+  }
+  return { nextStep, x, y, hmin, hmax, vmin, vmax };
+}