정렬해보기

2750번 문제 : 수 정렬하기

https://www.acmicpc.net/problem/2750

2751번 문제 : 수 정렬하기 2

https://www.acmicpc.net/problem/2751

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
 
int main() {
 
    int num;
    cin >> num;
    vector<int> v;
 
    while (num > 0)
    {
        int inp;
        cin >> inp;
        v.push_back(inp);
        num--;
    }
 
    sort(v.begin(), v.end());
    
    for (auto i : v)
    {
        cout << i << "\n";
    }
 
    return 0;
}

2108번 문제 : 통계학

https://www.acmicpc.net/problem/2108

#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
using namespace std;
 
vector<int> v;
int arr[8001] = {0};
 
int GetMean();
int GetMedian();
int GetMode();
int GetRange();
 
int main()
{
    int inp;
    cin >> inp;
 
    while (inp > 0)
    {
        int num;
        cin >> num;
        v.push_back(num);
        inp--;
    }
 
    cout << GetMean() << endl;
    cout << GetMedian() << endl;
    cout << GetMode() << endl;
    cout << GetRange() << endl;
 
    return 0;
}
 
int GetMean()
{
    int sum = 0;
    for (auto i : v)
        sum += i;
    
    double result = (double)sum / (double)v.size();
 
    return round(result);
}
 
int GetMedian()
{
    sort(v.begin(), v.end());
    int medianIndex = v.size() / 2; //v size is always odd number according to the question
 
    return v.at(medianIndex);
}
 
int GetMode()
{
    for (auto i : v)
    {
        if (i >= 0)
            arr[i]++;
        else
            arr[abs(i) + 4000]++;
    }
 
    int max = 0;
    int maxIndex = 0;
    bool isTheOnlyMax = false;
    for (int i = 0; i < sizeof(arr)/sizeof(*arr); i++) // sizeof(arr)/sizeof(*arr) = 8001
    {
        if (arr[i] == max)
            isTheOnlyMax = false;
 
        if (arr[i] > max)
        {
            max = arr[i];
            maxIndex = i;
            isTheOnlyMax = true;
        }
    }
 
    if (isTheOnlyMax)
    {
        int originalIndex;
        if (maxIndex > 4000)
            originalIndex = (maxIndex - 4000) * (-1);
        else
            originalIndex = maxIndex;
 
        return originalIndex;
    }
    else
    {
        vector<int> tempV;
        for (int i = 0; i < sizeof(arr) / sizeof(*arr); i++) // sizeof(arr)/sizeof(*arr) = 8001
        {
            if (arr[i] == max)
            {
                if(i < 4000)
                    tempV.push_back(i);
                else
                {
                    int value = (i - 4000) * (-1);
                    tempV.push_back(value);
                }
            }
        }
 
        sort(tempV.begin(), tempV.end());
 
        if (tempV.size() > 1) //TODO is this needed?
            return tempV[1];
        else
            return tempV[0];
    }
 
}
 
int GetRange()
{
    sort(v.begin(), v.end());
 
    return v.back() - v.front();
}

1427번 문제 : 소트인사이드

https://www.acmicpc.net/problem/1427

#include <iostream>
#include <algorithm>
#include <vector>
#include <functional>
using namespace std;
 
int main() {
 
    int num;
    cin >> num;
    vector<int> v;
 
    while (num > 0)
    {
        int leftover = num % 10;
        v.push_back(leftover);
        num /= 10;
    }
 
    sort(v.begin(), v.end(), greater<int>());
 
    for (auto i : v)
    {
        cout << i;
    }
 
    return 0;
}

메모: 

-greater<int>() 내림차순으로 정렬,   #include <functional> 헤더파일 필요

1181번 문제 : 단어정렬

https://www.acmicpc.net/problem/1181

#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
using namespace std;
 
bool Compare(const string& a, const string&b)
{
    //CompareStringAlphabetically
    if (a.size() == b.size()) {
 
        int i = 0;
        while (a[i] == b[i]) {
            i++;
            if (i >= a.size())
                break;
        }
        return(a[i] < b[i]);
    }
    //CompareStringByLength
    else
        return(a.size() < b.size());
}
 
int main() {
 
    int num;
    cin >> num;
    vector<string> v;
 
    while (num > 0)
    {
        string inp;
        cin >> inp;
        v.push_back(inp);        
        num--;
    }
 
    sort(v.begin(), v.end(), Compare); //vector sorting
    v.erase(unique(v.begin(), v.end()), v.end()); //erase duplication
 
    for (auto i : v)
    {
        cout << i << "\n";
    }
 
    return 0;
}

메모: 

-vector의 중복제거 함수는 unique사용

-unigue후에 뒷부분을 erase처리해야함