一、力扣01两数之和
<script type="text/javascript">
var twoSum = function(nums, target) {
let map = new Map()
for( let i=0
num = target - nums[i]
if( map.has(num) ){
return [map.get(num),i]
}
map.set(nums[i],i)
}
}
</script>
二、力扣217存在重复元素
<script type="text/javascript">
var containsDuplicate = function(nums) {
let set = new Set();
for( const x of nums ){
if( set.has(x) ){
return true;
}
set.add(x);
}
return false;
};
</script>
三、力扣349两个数组的交集
<script type="text/javascript">
var intersection = function(nums1, nums2) {
let set = new Set(nums2);
return [...new Set(nums1)].filter((val)=>set.has(val));
};
</script>
四、力扣1207独一无二的出现次数
<script type="text/javascript">
function fun( s ){
let maxNum = 0
let maxStr = ''
let map = new Map()
for( let item of s ){
map.set( item , (map.get(item) || 0 ) + 1 )
}
for(let [key,value] of map){
if( value > maxNum ){
maxStr = key
maxNum = value
}
}
return [maxStr , maxNum]
}
console.log( fun('aaabbbbccccccc') )
</script>
五、力扣03无重复字符的最长子串
<script type="text/javascript">
var lengthOfLongestSubstring = function(s) {
const map = new Map()
let l = 0
let num = 0
for( let i =0
if( map.has(s[i]) && map.get(s[i]) >= l ){
l = map.get(s[i]) + 1
}
num = Math.max( num , i+1-l )
map.set(s[i],i)
}
return num
}
</script>