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"
Write the code that will take a string and make this conversion given a number of rows:
string convert(string s, int numRows);
Example 1:
Input: s = "PAYPALISHIRING", numRows = 3
Output: "PAHNAPLSIIGYIR"
Example 2:
Input: s = "PAYPALISHIRING", numRows = 4
Output: "PINALSIGYAHRPI"
Explanation: P I N
A L S I G
Y A H R
P I
Accepted
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Submissions
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个人思路：
先计算出列数，用二维数组处理
然后分为字符落在竖和斜杠两种情况
竖：分为是否可以落满行的个数
斜杠同理
同时计算出当前竖的第一个值的列号
public String convert(String s, int numRows) {//ZigZag Conversion
int len=s.length();
if(numRows==1||s==null||s.equals(" ")||len<=numRows) return s;
else{
char[] result=new char[len];
char[] cs=s.toCharArray();
int cLen = 0;
int split1=2*(numRows-1);
int nDouble=len/split1;
if(len%split1==0){
cLen=(1+numRows-2)*nDouble;
}else if(len%split1<=numRows){
cLen=(1+numRows-2)*nDouble+1;
}else{
cLen=(1+numRows-2)*nDouble+(len%split1)-(numRows-1);
}
char[][] ch=new char[numRows][cLen];
int dif=split1;
for(int k=0;k<len;k++){
// System.out.println("start++++::::"+k);
if(k%dif==0){ //up start
int t=k>0?(k/2):0;
if(k+numRows>len){
for(int j=0;j<len-k;j++){
// System.out.println("45-----"+j+","+t+"="+(k+j));
ch[j][t]=cs[k+j];
}
k=len-1;
break;
}else{
for(int j=0;j<numRows;j++){
// System.out.println("52-----"+j+","+t+"="+(k+j));
ch[j][t]=cs[k+j];
}
k=k+numRows-2;
}
}else if((k%dif==(numRows-1))){//down start
// System.out.println(k);
int t=k+1-numRows>0?((k+1-numRows)/2):0;
int tt=numRows-1;
if(k+numRows-2>=len){
for(int j=0;j<len-k-1;j++){
--tt;
++t;
// System.out.println("64-----"+tt+","+t+"="+cs[k+j+1]);
ch[tt][t]=cs[k+j+1];
}
k=len-1;
break;
}else{
for(int j=0;j<numRows-2;j++){
--tt;
++t;
// System.out.println("t:"+tt);
// System.out.println("70-----"+tt+","+t+"="+cs[k+j+1]);
ch[tt][t]=cs[k+j+1];
}
k=k+numRows-2;
// System.out.println("79----"+k);
}
}
}
int next=0;
for(int i=0;i<ch.length;i++){
for(int j=0;j<ch[0].length;j++){
// System.out.print(ch[i][j]);
if(ch[i][j]!='\u0000'){
result[next++]=ch[i][j];
}
}
}
return new String(result);
}
}