Longest common sub-sequence LCS

1  PackageDynamicprogram;2 3 Importorg.junit.Test;4 5 6  Public classLCS {7 8     //enter two series to find the longest common sub-sequence9     //B and C two arrays one is used to save the result of the calculation, one to save the pathTen     //Array B uses 1 for top left, 2 for top, and 3 for left One      Public voidLcslength (int[] Rows,int[] cols,int[] [] B,int[] [] c) { A         intRowslength =rows.length; -         intColslength =cols.length; -          for(inti = 1; i < rowslength; ++i) { the              for(intj = 1; J < Colslength; ++j) { -                 if(Rows[i] = =Cols[j]) { -C[I][J] = c[i-1][j-1] + 1; -B[I][J] = 1; +                 } -                 Else if(C[i][j-1] > C[i-1][j]) { +C[I][J] = c[i][j-1]; AB[I][J] = 2; at                 } -                 Else { -C[I][J] = c[i-1][j]; -B[I][J] = 3; -                 } -             } in         } -     } to      +      Public voidPrintlcs (int[] [] B,int[] Rows,intIintj) { -         if(i = = 0 | | j = 0) { the             return; *         } $         if(B[i][j] = = 1) {Panax NotoginsengSystem.out.println ((Char) rows[i]); -Printlcs (b, rows, i-1, j-1); the         } +         Else if(B[i][j] = = 2) { APrintlcs (b, rows, I, j-1); the         } +         Else  -Printlcs (b, rows, i-1, j); $              $     } -      - @Test the      Public voidTest () { -         //index value for subscript 0 is temporarily unusedWuyi         int[] cols = {-1, ' A ', ' B ', ' C ', ' B ', ' D ', ' A ', ' B '}; the         int[] rows = {-1, ' B ', ' D ', ' C ', ' A ', ' B ', ' a '}; -         //preparatory work Wu         //in fact, the spatial complexity of the algorithm can be further optimized -         intRowslength =rows.length; About         intColslength =cols.length; $         //declares an array of two m rows n columns, because the array's subscript 0 is not used, otherwise the length of the array is required +1 -         //used to record some additional path information. -         int[] Path =New int[rowslength][colslength]; -         //used to record sub-problems, that is, the length of the oldest sequence A         int[] len =New int[rowslength][colslength]; +          for(intj = 0; J < Rowslength; ++j) theLen[j][0] = 0; -          for(inti = 0; i < colslength; ++i) $Len[0][i] = 0; the lcslength (rows, cols, path, Len); the         //System.out.println (len[rowslength-1][colslength-1]); the         //Note that this printout of an optimal LCS reverse-sequence output thePrintlcs (path, rows, RowsLength-1, colsLength-1); -     } in}

Longest common sub-sequence LCS