春节刷题day15：LeetCode
剑指 Offer 38. 字符串的排列
424. 替换后的最长重复字符
978. 最长湍流子数组
5668. 最长的美好子字符串
594. 最长和谐子序列
1、剑指 Offer 38. 字符串的排列
class Solution {
public:
bool vis[10];
vector<char> ans;
vector<string> now;
unordered_map<string, bool> pa;
void slove(string s){
if((int)ans.size() == (int)s.size()){
string ss;
for(int i = 0; i < ans.size(); i++) ss += ans[i];
if(pa.count(ss) == 0){
now.push_back(ss);
pa[ss] = true;
}
}
for(int i = 0; i < s.size(); i++){
if(!vis[i]){
vis[i] = true;
ans.push_back(s[i]);
slove(s);
vis[i] = false;
ans.pop_back();
}
}
}
vector<string> permutation(string s) {
slove(s);
return now;
}
};
2、424. 替换后的最长重复字符
class Solution {
public:
int characterReplacement(string s, int k) {
int size = s.size();
vector<int> v(26, 0);
int l = 0, r = 0, Max = 0;
for(; r < size; r++){
v[s[r] - 'A']++;
Max = max(Max, v[s[r] - 'A']);
if(r - l + 1 > Max + k){
v[s[l] - 'A']--; l++;
}
}
return r - l;
}
};
3、978. 最长湍流子数组
class Solution {
public:
int maxTurbulenceSize(vector<int>& arr) {
int l = 1, r = 1, ans = 1;
int size = arr.size();
for(int i = 1; i < size; i++){
if(arr[i] > arr[i - 1]){
l = r + 1; r = 1;
}else if(arr[i] < arr[i - 1]){
r = l + 1; l = 1;
}else{
l = r = 1;
}
ans = max(ans, max(l, r));
}
return ans;
}
};
4、5668. 最长的美好子字符串
class Solution {
public:
string longestNiceSubstring(string s) {
int len = s.size();
int k = 0;
string ans;
for(int i = 0; i < len; i++){
int l = 0, r = 0;
for(int j = i; j < len; j++){
if(s[j] >= 'a' && s[j] <= 'z') l |= (1 << (s[j] - 'a'));
else r |= (1 << (s[j] - 'A'));
if(l == r && j - i + 1 > k){
k = j - i + 1; ans = s.substr(i, k);
}
}
}
return ans;
}
};
5、594. 最长和谐子序列
class Solution {
public:
map<int, int> pa;
int findLHS(vector<int>& nums) {
int size = nums.size();
for(int i = 0; i < size; i++) pa[nums[i]]++;
map<int, int>::iterator it = pa.begin(), IT = pa.begin();
int ans = 0; it++;
for(; it != pa.end(); it++, IT++){
if(abs(it -> first - IT -> first) == 1) ans = max(ans, it -> second + IT -> second);
}
return ans;
}
};
2021/2/21完结。