13 Code commit

Goldman Sachs/13RhombusSumsinaGRID.cpp

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+// 1878. Get Biggest Three Rhombus Sums in a Grid
+// You are given an m x n integer matrix grid​​​.
+
+// A rhombus sum is the sum of the elements that form the border of a regular rhombus shape in grid​​​. The rhombus must have the shape of a square rotated 45 degrees with each of the corners centered in a grid cell. Below is an image of four valid rhombus shapes with the corresponding colored cells that should be included in each rhombus sum:
+// Note that the rhombus can have an area of 0, which is depicted by the purple rhombus in the bottom right corner.
+// Return the biggest three distinct rhombus sums in the grid in descending order. If there are less than three distinct values, return all of them.
+
+// Example 1:
+// Input: grid = [[3,4,5,1,3],[3,3,4,2,3],[20,30,200,40,10],[1,5,5,4,1],[4,3,2,2,5]]
+// Output: [228,216,211]
+// Explanation: The rhombus shapes for the three biggest distinct rhombus sums are depicted above.
+// - Blue: 20 + 3 + 200 + 5 = 228
+// - Red: 200 + 2 + 10 + 4 = 216
+// - Green: 5 + 200 + 4 + 2 = 211
+
+// Example 2:
+// Input: grid = [[1,2,3],[4,5,6],[7,8,9]]
+// Output: [20,9,8]
+// Explanation: The rhombus shapes for the three biggest distinct rhombus sums are depicted above.
+// - Blue: 4 + 2 + 6 + 8 = 20
+// - Red: 9 (area 0 rhombus in the bottom right corner)
+// - Green: 8 (area 0 rhombus in the bottom middle)
+// Example 3:
+
+// Input: grid = [[7,7,7]]
+// Output: [7]
+// Explanation: All three possible rhombus sums are the same, so return [7].
+
+class Solution {
+public:
+    int solve(vector<vector<int>>& grid,int l,int r,int u,int d){
+        int c1 = (l+r)/2,c2=(l+r)/2,sum=0;
+        bool flag = true;
+
+        for(int row = u;row<=d;row++)
+        {
+            if(c1 == c2) sum += grid[row][c1];
+            else sum += grid[row][c1] + grid[row][c2];
+            if(c1 == l && c2==r) flag = false;
+            if(flag) c1--,c2++;
+            else c1++,c2--;
+        }
+
+        return sum;
+    }
+
+    vector<int> getBiggestThree(vector<vector<int>>& grid) {
+        int m = grid.size(),n=grid[0].size();
+        set<int> st;
+        for(int i=0;i<m;i++){
+            for(int j=0;j<n;j++){
+                int l=j,r=j,d=i; 
+                while(l>=0 && r<n && d<m){
+                    int sum = solve(grid,l,r,i,d);
+                    l--; r++; d += 2;
+                    if(st.size() < 3) st.insert(sum);
+                    else if(st.size() == 3 && st.count(sum)==0 && sum > *(st.begin())) {
+                        st.erase(st.begin());
+                        st.insert(sum);
+                    }
+                }
+            }
+        }
+
+        vector<int> ans;
+        for(int it : st){
+            ans.push_back(it);
+        }
+        reverse(ans.begin(),ans.end());
+        return ans;
+    }
+};