leetCode刷题(将字符串转成W形状的字符串再以Z形字符串输出)

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 text, int nRows);

convert("PAYPALISHIRING", 3) should return "PAHNAPLSIIGYIR".

/**
 * @param {string} s
 * @param {number} numRows
 * @return {string}
 */
var convert = function(s, numRows) {
    var y=0;
    var storeArr=[];
    if(numRows==1){
        return s;
    }
    for(var i=0;i<s.length;i++){
        storeArr[y]=(storeArr[y]||"")+""+s[i];
        y==0?(flag=true):"";
        y==(numRows-1)?(flag=false):"";
        flag?y++:y--;
    }
    return storeArr.join("");
};