[algorithm] cyclic printing matrix, serpentine Matrix special topic

1. Cyclic Print matrix

For example, provide the following matrices:

Print them in the following order:

1 2 3 4 8 12 16 15 14 13 9 5 6 7 11 10

This question directly write also no problem, is particularly prone to error, a little attention to write wrong, and this type of question I want a universal solution.

One way I think of it is to print a lap, from outside to inside, we determine a rectangle, usually through the coordinates of the upper left corner and the coordinates of the lower right corner, namely (TR,TC) and (DR,DC), we first write the method of printing a circle, and then loop the call, If we find that the coordinates of the upper-left corner go to the right or bottom of the lower-right coordinate, the whole process stops, so the extra space complexity is O (1). No bibi,show me the code.

 PackageCom.darrenchan;/*** Circular Print Matrix *@authorThink **/ Public classSheXingPrint2 { Public Static voidMain (string[] args) {int[] m =New int[][]{{1,2,3,4},{5,6,7,8},{9,10,11,12},{13,14,15,16}}; intTR = 0, TC = 0, DR = 0, DC = 3;  while(TR <= DR && TC <=DC) {Printedge (M, TR+ +, tc++, DR--, dc--); }    }         Public Static voidPrintedge (int[] m,intTrintTcintDR,intDC) {        if(TR = =DR) {             for(inti = TC; I <= DC; i++) {System.out.print (M[tr][i]+ " "); }        }Else if(TC = =DC) {             for(inti = TR; I <= DR; i++) {System.out.print (M[I][TC]+ " "); }        }Else{            intCurrow =TR; intCurcol =TC;  while(Curcol! =DC) {System.out.print (M[tr][curcol]+ " "); Curcol++; }             while(Currow! =DR) {System.out.print (M[CURROW][DC]+ " "); Currow++; }                         while(Curcol! =TC) {System.out.print (M[dr][curcol]+ " "); Curcol--; }                         while(Currow! =TR) {System.out.print (M[CURROW][TC]+ " "); Currow--; }                    }    }}

2. Serpentine Matrix

Give a number, for example, 4, to generate the following matrix directly:

The idea is similar to the previous, just slightly changed:

 PackageCom.darrenchan;/*** Print the Serpentine Matrix *@authorThink **/ Public classSheXingPrint3 { Public Static intnum = 1;  Public Static voidMain (string[] args) {//given how big the number is, how much of a matrix is constructed        int[] m =New int[4] [4]; intTR = 0, TC = 0, DR = 3, DC = 3;  while(TR <= DR && TC <=DC) {Generateedge (M, TR+ +, tc++, DR--, dc--); }                 for(inti = 0; i < m.length; i++) {             for(intj = 0; J < M[i].length; J + +) {System.out.print (M[i][j]+ "\ T");        } System.out.println (); }    }     Public Static voidGenerateedge (int[] m,intTrintTcintDR,intDC) {intCurrow =TR; intCurcol =TC;  while(Curcol! =DC) {M[tr][curcol]=num; Num++; Curcol++; }         while(Currow! =DR) {M[CURROW][DC]=num; Num++; Currow++; }         while(Curcol! =TC) {M[dr][curcol]=num; Num++; Curcol--; }         while(Currow! =TR) {M[CURROW][TC]=num; Num++; Currow--; }    }}

[algorithm] cyclic printing matrix, serpentine Matrix special topic