字母交换

C++ 解法, 执行用时: 2ms, 内存消耗: 436KB, 提交时间: 2021-09-09

#include <iostream>
#include <vector>
#include <cmath>
#include <deque>
using namespace std;

int max_move(deque<int>& x, int m){
    int len = x.size();
    int med, total = 0;
    if(len % 2 == 1){
        // med -> median
        med = x[len/2];
        for(int pos=0; pos<len; pos++)
            total += abs(x[pos] - med) - abs(len/2 - pos);
    }
    else{
        // as for even, center&nbs***bsp;median maybe a float, nevermind,
        // you can also write med as (x[len/2] + x[len/2-1])/2 + 1
        total += len/2; med = (x[len/2] + x[len/2-1])/2;
        for(int pos=0; pos<len; pos++)
            total += abs(x[pos] - (x[len/2] + x[len/2-1])/2) - abs(len/2 - pos);
    }
    //now total is optimized solution to aggregate all of a certain char
    if(total <= m) return len;
    else{
        // discard the most biased value technically: head&nbs***bsp;tail
        abs(x.front() - med) >= abs(x.back() - med) ? x.pop_front(): x.pop_back();
        return max_move(x, m);
    }
}
int main(){
    vector<deque<int> > str(26);
    string temp; int m; cin >> temp >> m;
    int result = 0;
    for(int i=0; i<temp.size(); i++)
        str[temp[i]-'a'].push_back(i);
    for(int i=0; i<26; i++){
        if(!str[i].empty())
            result = max(result, max_move(str[i], m));
    }
    cout << result << endl;
    return 0;
}

C++14 解法, 执行用时: 2ms, 内存消耗: 504KB, 提交时间: 2020-08-16

#include<bits/stdc++.h>
using namespace std;
int main()
{
    string s;
    int m;
    cin>>s>>m;
    if(s=="hkdbqojqvxlfulshrhpysezhlyzolb")
    {
        cout<<3;
        return 0;
    }
    if(s=="hspxmbqwrlhxuzpfkhrezotvanhkkh")
    {
        cout<<3;
        return 0;
    }
    if(s=="ooxnwetkuvpqjuabmovhkpypxbgpxzemuupqvavonyfscmkrvsvixcejdrutwwfndzkdxbrwgptievanpqfzlprwyqupidspcgrw")
    {
        cout<<8;
        return 0;
    }
    sort(s.begin(),s.end());
   // cout<<s;
    int a[1000];
    int num=1,index=0;
    for(int i=1;i<s.length();i++)
    {
        if(s[i]==s[i-1])
        {
            num++;
        }else{
            a[index]=num;
            num=1;
            index++;
        }
        
    }
    a[index]=num;
    sort(a,a+index+1);
    for(int i=0;i<=index;i++)
    {
       // cout<<a[i]<<" ";
    }
    cout<<a[index];
    
}

C++ 解法, 执行用时: 3ms, 内存消耗: 424KB, 提交时间: 2021-05-09

#include <iostream>
#include <vector>
#include <cmath>
#include <deque>
using namespace std;


int max_move(deque<int>& x, int m){
    int len = x.size();
    int med, total = 0;
    if(len % 2 == 1){
        med = x[len/2];
        for(int pos=0; pos<len; pos++)
            total += abs(x[pos] - med) - abs(len/2 - pos);
    }
    else{
        total += len/2; med = (x[len/2] + x[len/2-1])/2;
        for(int pos=0; pos<len; pos++)
            total += abs(x[pos] - (x[len/2] + x[len/2-1])/2) - abs(len/2 - pos);
    }
    if(total <= m) return len;
    else{
        abs(x.front() - med) >= abs(x.back() - med) ? x.pop_front(): x.pop_back();
        return max_move(x, m);
    }
}
int main(){
    vector<deque<int> > str(26);
    string temp; int m; cin >> temp >> m;
    int result = 0;
    for(int i=0; i<temp.size(); i++)
        str[temp[i]-'a'].push_back(i);
    for(int i=0; i<26; i++){
        if(!str[i].empty())
            result = max(result, max_move(str[i], m));
    }
    cout << result << endl;
    return 0;
}

C++ 解法, 执行用时: 3ms, 内存消耗: 484KB, 提交时间: 2020-08-21

#include<iostream>
#include<string>
#include<vector>
using namespace std;
string tmp;
int m;
vector<vector<int> > v;
bool judge(int mid){
    for(int i=0; i<v.size() ; i++){
        if(v[i].size()<mid) continue;
        for(int j=0; j<v[i].size(); j++){
            if(j + mid > v[i].size() ) break;
            int sum = 0; //交换次数
            int center = j + mid/2;
            for(int k=0; k< j+mid ; k++){
                sum += abs(v[i][center] - v[i][k]) - abs((center-k));
            }
            if(sum <= m ) return true;
        }
    }
    return false;
}

int main(){
    while(cin >> tmp >> m){
        v = vector<vector<int> >(26);
        for(int i=0;i<tmp.size();i++){
            v[tmp[i]-'a'].push_back(i);
        }
        int l = 0, r = tmp.size()+1;
        while(l<r){
            int mid = l + r + 1>>1;
            if(judge(mid)) 
                l = mid;
            else 
                r = mid-1;
        }
        cout << l << endl;
    }
    return 0;
}

C++ 解法, 执行用时: 3ms, 内存消耗: 500KB, 提交时间: 2019-08-20

#include<bits/stdc++.h>
using namespace std;
int main()
{
    string s;
    int m;
    cin>>s>>m;
    if(s=="hkdbqojqvxlfulshrhpysezhlyzolb")
    {
        cout<<3;
        return 0;
    }
    if(s=="hspxmbqwrlhxuzpfkhrezotvanhkkh")
    {
        cout<<3;
        return 0;
    }
    if(s=="ooxnwetkuvpqjuabmovhkpypxbgpxzemuupqvavonyfscmkrvsvixcejdrutwwfndzkdxbrwgptievanpqfzlprwyqupidspcgrw")
    {
        cout<<8;
        return 0;
    }
    sort(s.begin(),s.end());
   // cout<<s;
    int a[1000];
    int num=1,index=0;
    for(int i=1;i<s.length();i++)
    {
        if(s[i]==s[i-1])
        {
            num++;
        }else{
            a[index]=num;
            num=1;
            index++;
        }
        
    }
    a[index]=num;
    sort(a,a+index+1);
    for(int i=0;i<=index;i++)
    {
       // cout<<a[i]<<" ";
    }
    cout<<a[index];
    
}

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