Create minimum-sideway-jumps.cpp

Author: kamyu104

C++/minimum-sideway-jumps.cpp

@@ -0,0 +1,23 @@
+// Time:  O(n)
+// Space: O(1)
+
+class Solution {
+public:
+    int minSideJumps(vector<int>& obstacles) {
+        static const int MAX_N = 5 * 1e5;
+        static const int INF = (MAX_N - 1) + 1;
+
+        array<int, 3> dp{1, 0, 1};
+        for (const auto& i : obstacles) {
+            if (i) {
+                dp[i - 1] = INF;
+            }
+            for (int j = 0; j < 3; ++j) {
+                if (j + 1 != i) {
+                    dp[j] = min({dp[0] + (j != 0), dp[1] + (j != 1), dp[2] + (j != 2)});
+                }
+            }
+        }
+        return *min_element(cbegin(dp), cend(dp));
+    }
+};