title: 2259. Remove Digit From Number to Maximize Result
tags:
- backtracking
categories: leetcode
comments: false
class Solution {
public:
string removeDigit(string number, char digit) {
vector<int> count;
int n = number.size();
for(int i=0;i<n;++i){
if(number[i] == digit) count.push_back(i);
}
vector<string> ret;
for(auto d:count){
string str ;
for(int i=0;i<n;++i){
if(i!=d) str+=number[i];
}
ret.push_back(str);
}
sort(ret.begin(), ret.end());
return ret[ret.size()-1];
}
};
class Solution {
public:
string removeDigit(string number, char digit) {
int n = number.size();
for(int i=0;i<n-1;++i){
if(number[i] == digit && number[i+1]>digit){
return number.substr(0,i) +number.substr(i+1);
}
}
// find last digit
int last_d = number.find_last_of(digit);
return number.substr(0,last_d)+number.substr(last_d+1);
}
};
- option 1
- time complexity
O(nlogn)
- space complexity
O(n^2)
- option 2
- time complexity
O(n)
- space complexity
O(1)