[leetcode] 498. Diagonal Traverse -- JavaScript 代码

var findDiagonalOrder = function(matrix) {
    var result = [];
    var row = matrix.length;
    if(row === 0){
        return result;
    }
    var col = matrix[0].length;
    var rIndex = 0;
    var cIndex = 0;
    var m = 0;//almostUseless
    while(!(rIndex==row-1 && cIndex==col-1)){
        result.push(matrix[rIndex][cIndex]);
        if((rIndex+cIndex)%2 === 0){//处于上升行 
            (rIndex-1<0) ? (cIndex+1>col-1?(rIndex++):(cIndex++)) : (cIndex+1>col-1?(rIndex+1>row-1?m++:rIndex++):(cIndex++,rIndex--));
        }else{//处于下降行
            (rIndex+1>row-1) ? (cIndex+1>col-1?m++:(cIndex++)) : (cIndex-1<0?(rIndex++):(rIndex++,cIndex--));
        }
    }
    result.push(matrix[row-1][col-1]);
    return result;
};

这道题我是采用了连续的三元运算符来进行判断，将整个正方形区域分为了左右上下边界以及中间的部分，通过坐标 rIndex+cIndex 的值来判断当前是出于上升行还是下降行。