第37篇

1、手写数组快速排序

var quickSort = function (arr) {
  if (arr.length <= 1) {
    return arr;
  }

  var pivotIndex = Math.floor(arr.length / 2);
  var pivot = arr.splice(pivotIndex, 1)[0];
  var left = [];
  var right = [];
  for (var i = 0; i < arr.length; i++) {
    if (arr[i] < pivot) {
      left.push(arr[i]);
    } else {
      right.push(arr[i]);
    }
  }

  return quickSort(left).concat([pivot], quickSort(right));
}

2、判断一个字符串中出现次数最多的字符，并统计次数

var str = "shdshdfjkfjfdgjkjdksgjskdjfsfsfsfjksjkfdkjf";
var arr = str.split("").sort(); //把字符串变为数组，在排序
str = arr.join("");
var count = 0;
var char = 0;
var reg = /(w)1+/g;

str.replace(reg, function (parent, son) {
  if (parent.length > count) {
    count = parent.length;
    char = son;
  }
});

console.log("最多的字符为：" + char + ";个数为：" + count);