[leet] 329 Longest Increasing Path in a Matrix (hard)

Author: hyeonbinHur

허현빈/3주차/260116.js

@@ -0,0 +1,41 @@
+var longestIncreasingPath = function (matrix) {
+  const grid = matrix;
+  let max = 0;
+  const dir = [
+    [0, 1],
+    [0, -1],
+    [1, 0],
+    [-1, 0],
+  ];
+  const set = new Set();
+  matrix.map((e) => e.map((e2) => set.add(e2)));
+  const newArr = Array.from(set).sort((a, b) => a - b);
+  const map = new Map(newArr.map((e, i) => [e, i + 1]));
+  const backtrackin = (k, row, col) => {
+    if (k > max) {
+      max = k;
+    }
+    for (let i = 0; i < 4; i++) {
+      const nx = col + dir[i][1];
+      const ny = row + dir[i][0];
+      if (
+        nx >= 0 &&
+        ny >= 0 &&
+        nx < grid[0].length &&
+        ny < grid.length &&
+        grid[ny][nx] > grid[row][col]
+      ) {
+        const val = map.get(grid[ny][nx]);
+        if (k + newArr.length - val + 1 > max) {
+          backtrackin(k + 1, ny, nx);
+        }
+      }
+    }
+  };
+  for (let i = 0; i < grid.length; i++) {
+    for (let j = 0; j < grid[0].length; j++) {
+      backtrackin(1, i, j);
+    }
+  }
+  return max;
+};