[Leetcode] Maximal Rectangle

This link shares a nice solution with explanation using DP. You'll be a clear of the algorithm after running it in its suggested example:

Matrix = [[0,0,0,1,0,0,0],[0,0,1,1,1,0,0],[0,1,1,1,1,1,0]];

The code is rewritten as follows.

1 classSolution {2  Public:3     intMaximalrectangle (vector<vector<Char>>&matrix) {4         if(Matrix.empty ())return 0;5         Const intm = Matrix.size (), n = matrix[0].size ();6         int*left =New intN (), *right =New intN (), *height =New int[n] ();7 Fill_n (right, n, N);8         intArea =0;9          for(inti =0; I < m; i++) {Ten             intL =0, r =N; One              for(intj =0; J < N; J + +) AHEIGHT[J] + = matrix[i][j] = ='1'?1: -Height[j]; -              for(intj =0; J < N; J + +) { -                 if(Matrix[i][j] = ='1') Left[j] =Max (Left[j], L); the                 ElseLEFT[J] =0, L = j +1; -             } -              for(intj = N-1; J >=0; j--) { -                 if(Matrix[i][j] = ='1') Right[j] =min (right[j], R); +                 ElseRight[j] = N, r =J; -             } +              for(intj =0; J < N; J + +) AArea = max (area, (Right[j]-left[j]) *height[j]); at         } -         returnArea ; -     } -};

[Leetcode] Maximal Rectangle