在数组JavaScript中查找子数组的出现的次数
字面值数组的度数定义为其任何一个元素的最大频率。
const arr = [1, 2, 3, 3, 5, 6, 4, 3, 8, 3];
该数组的次数为4，因为在此数组中3重复了4次。
我们需要编写一个包含一组文字的JavaScript函数。我们函数的任务是从度数与整个数组相同的数组中找到最小连续子数组的长度。
示例
const arr = [1, 2, 3, 3, 5, 6, 4, 3, 8, 3];
const findShortestSubArray = (arr = []) => {
let range = new Map(), maxDegree = 0, minLength = Infinity;
for(let i = 0; i < arr.length; i++){ if(range.has(arr[i])) {
let start = range.get(arr[i])[0];
let degree = range.get(arr[i])[2]; degree++;
range.set(arr[i], [start, i, degree]);
if(degree > maxDegree)
maxDegree = degree;
}
else {
let degree = 1;
range.set(arr[i],[i, i, degree]); if(degree > maxDegree)
maxDegree = degree;
}
}
for (let key of range.keys()){
let val = range.get(key)
if(val[2] === maxDegree){
let diff = (val[1] - val[0]) + 1;
if(diff < minLength) minLength = diff;
}
}
return minLength;
};
console.log(findShortestSubArray(arr));输出结果
8