leetcode_num6_Zigzag

The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)

P   A   H   N
A P L S I I G
Y   I   R

And then read line by line: "PAHNAPLSIIGYIR"

找规律

#include<iostream>
#include<string>
using namespace std;
void Line(string s,string *res,int length,int cyclelen,int index,int nRows);
string convert(string s, int nRows) {
	int length=s.length();
	if(length<=0||nRows<0)
		return NULL;
	if(nRows==0||nRows==1)
		return s;
	int cyclelen=2*nRows-2;
	string *res=new string[nRows];
	for(int i=0;i<nRows;i++)
		res[i]="";
	Line(s,res,length,cyclelen,0,nRows);
	Line(s,res,length,cyclelen,nRows-1,nRows);
	if(nRows>2){
		for(int i=1;i<nRows-1;i++)
			Line(s,res,length,cyclelen,i,nRows);
	}
	string result;
	for(int i=0;i<nRows;i++)
		result+=res[i];
	return result;
        
}
void Line(string s,string *res,int length,int cyclelen,int index,int nRows){
	if((index==0)||(index==nRows-1)){
		int j=index;
		while(j<length){
			res[index]+=s[j];
			j+=cyclelen;
		}
	}
	else{
		int j=index;
		int k=cyclelen-j;
		while(j<length||k<length){
			if(j<length)
				res[index]+=s[j];
			else
				break;
			if(k<length)
				res[index]+=s[k];
			else
				break;
			j+=cyclelen;
			k+=cyclelen;
		}
	}
}
void main(){
	string s="PAYPALISHIRING";
	string result=convert(s,3);
	cout<<result<<endl;
	system("pause");
}

leetcode_num6_Zigzag

原文：http://blog.csdn.net/eliza1130/article/details/44680499