Lecture 116: Min Score Triangulation of Polygon

Lectures/Lecture_116/Lecture_Codes/1039_1.cpp

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+// recusion --> gives TLE
+
+class Solution {
+public:
+    int solve(vector<int> &values, int i, int j) {
+        if (i+1 == j) {
+            return 0;
+        }
+
+        int ans = INT_MAX;
+
+        for (int k=i+1; k<j; k++) {
+            ans = min(ans, values[i]*values[j]*values[k] + solve(values, i, k) + solve(values, k, j));
+        }
+
+        return ans;
+    }
+
+    int minScoreTriangulation(vector<int>& values) {
+        int n = values.size();
+        return solve(values, 0, n-1);
+    }
+};

Lectures/Lecture_116/Lecture_Codes/1039_2.cpp

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+// recursion + memoization
+
+class Solution {
+public:
+    int solve(vector<int> &values, int i, int j, vector<vector<int>> &dp) {
+        if (i+1 == j) {
+            return 0;
+        }
+
+        if (dp[i][j] != -1) {
+            return dp[i][j];
+        }
+
+        int ans = INT_MAX;
+
+        for (int k=i+1; k<j; k++) {
+            ans = min(ans, values[i]*values[j]*values[k] + solve(values, i, k, dp) + solve(values, k, j, dp));
+        }
+
+        dp[i][j] = ans;
+
+        return dp[i][j];
+    }
+
+    int minScoreTriangulation(vector<int>& values) {
+        int n = values.size();
+        vector<vector<int>>dp(n, vector<int>(n, -1));
+        return solve(values, 0, n-1, dp);
+    }
+};

Lectures/Lecture_116/Lecture_Codes/1039_3.cpp

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+// tabulation method
+
+class Solution {
+public:
+    int solve(vector<int> &values) {
+        int n = values.size();
+
+        vector<vector<int>>dp(n, vector<int>(n, 0));
+
+        for (int i=n-1; i>=0; i--) {
+            for (int j=i+2; j<n; j++) {
+                int ans = INT_MAX;
+
+                for (int k=i+1; k<j; k++) {
+                    ans = min(ans, values[i]*values[j]*values[k] + dp[i][k] + dp[k][j]);
+                }
+
+                dp[i][j] = ans;
+            }
+        }
+
+        return dp[0][n-1];
+    }
+
+    int minScoreTriangulation(vector<int>& values) {
+
+        return solve(values);
+    }
+};

Lectures/Lecture_116/Lecture_Codes/README.md

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+# Lecture Codes
+
+|  **Problem**  |  **Solution**  |  **Level**  |
+|:--------------|:--------------:|:-----------:|
+|  [1039. Minimum Score Triangulation of Polygon](https://leetcode.com/problems/minimum-score-triangulation-of-polygon/description/)  |  [Solution1](), [Solution2](), [Solution3]()  |  Medium  |