leetcode

commit 169c8dcb61f73078f5dba6ab2311594d039608e2
parent fe5cef57411cfa6b4ca76ea452efde89b1e50dcc
Author: Dimitrije Dobrota <mail@dimitrijedobrota.com>
Date:   Sat,  4 Feb 2023 14:51:30 +0100

Dynamic Programming I: Day 15

Diffstat:
A
Problems/0063.cpp
 | 
29
+++++++++++++++++++++++++++++
M
README.md
 | 
1
+

2 files changed, 30 insertions(+), 0 deletions(-)
diff --git a/Problems/0063.cpp b/Problems/0063.cpp
@@ -0,0 +1,29 @@
+class Solution {
+public:
+  int uniquePathsWithObstacles(vector<vector<int>> &obstacleGrid) {
+    int n = obstacleGrid.size(), m = obstacleGrid[0].size();
+    vector<vector<long>> mat(n, vector<long>(m, 0));
+    for (int i = 0; i < n; i++)
+      for (int j = 0; j < m; j++)
+        if (obstacleGrid[i][j]) mat[i][j] = -1;
+
+    if (mat[n - 1][m - 1] == -1) return 0;
+    if (mat[0][0] == -1) return 0;
+
+    queue<pair<int, int>> q;
+    q.push({n - 1, m - 1}), mat[n - 1][m - 1] = 1;
+    while (!q.empty()) {
+      auto [x, y] = q.front();
+      q.pop();
+      if (x - 1 >= 0 && mat[x - 1][y] != -1) {
+        mat[x - 1][y] += mat[x][y];
+        if (mat[x - 1][y] == mat[x][y]) q.push({x - 1, y});
+      }
+      if (y - 1 >= 0 && mat[x][y - 1] != -1) {
+        mat[x][y - 1] += mat[x][y];
+        if (mat[x][y - 1] == mat[x][y]) q.push({x, y - 1});
+      }
+    }
+    return (int)mat[0][0];
+  }
+};
diff --git a/README.md b/README.md
@@ -59,6 +59,7 @@ for solving problems.
 |  0059  |   Medium   | [Spiral Matrix II](Problems/0059.cpp)                                                            |
 |  0061  |   Medium   | [Rotate List](Problems/0061.cpp)                                                                 |
 |  0062  |   Medium   | [Unique Paths](Problems/0062.cpp)                                                                |
+|  0063  |   Medium   | [Unique Paths II](Problems/0063.cpp)                                                             |
 |  0066  |    Easy    | [Plus One](Problems/0066.cpp)                                                                    |
 |  0067  |    Easy    | [Add Binary](Problems/0067.cpp)                                                                  |
 |  0070  |    Easy    | [Climbing Stairs](Problems/0070.cpp)                                                             |