From 05c1800c4d1f823d73fd58ffc2caf7b0cdaddf0a Mon Sep 17 00:00:00 2001
From: Matej Focko <mfocko@redhat.com>
Date: Tue, 2 Aug 2022 11:40:31 +0200
Subject: [PATCH] problems: add unique paths

Signed-off-by: Matej Focko <mfocko@redhat.com>
---
 problems/unique-paths.cpp | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 problems/unique-paths.cpp

diff --git a/problems/unique-paths.cpp b/problems/unique-paths.cpp
new file mode 100644
index 0000000..31c2358
--- /dev/null
+++ b/problems/unique-paths.cpp
@@ -0,0 +1,27 @@
+class Solution {
+    int right(const std::vector<int>& row, int size, int idx) const
+    {
+        if (idx >= size) {
+            return 0;
+        }
+        return row[idx];
+    }
+
+public:
+    int uniquePaths(int m, int n)
+    {
+        std::vector<int> bottom(n, 1);
+
+        for (int y = m - 2; y >= 0; y--) {
+            std::vector<int> above(n, 0);
+
+            for (int x = n - 1; x >= 0; x--) {
+                above[x] = right(above, n, x + 1) + bottom[x];
+            }
+
+            bottom = std::move(above);
+        }
+
+        return bottom[0];
+    }
+};