NPC系列文章（2)---最小覆盖问题Set Cover Problem的一种贪心算法求全部覆盖集

最新推荐文章于 2025-04-23 12:38:41 发布

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最新推荐文章于 2025-04-23 12:38:41 发布 · 355 阅读

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#贪心算法 #算法

QT = core

CONFIG += c++11 cmdline

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
        cprecisetimer.cpp \
        main.cpp \
        simplegraph.cpp

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

HEADERS += \
    commondatastructure.h \
    cprecisetimer.h \
    simplegraph.h

#ifndef COMMONDATASTRUCTURE_H
#define COMMONDATASTRUCTURE_H

#include <iostream>
#include <vector>
#include <set>
#include <utility>
#include <map>
#include <list>

#include "assert.h"
//using namespace std;

const int MAXVERTEX = 40;

typedef std::set<int> ADJPOINTSSET;  //相邻顶点集合
typedef std::pair<int, ADJPOINTSSET> ADJPOINTSPAIR; //相邻顶点集合与其基数（大小）
typedef std::map<int, ADJPOINTSPAIR> VERTEXMAP;  //顶点与它的相邻顶点集合的映射
typedef VERTEXMAP GRAPH_ADJLIST_MAP; //G的邻接表List表示

typedef std::vector<std::vector<bool> > GRAPH_ADJARRAY_VECTOR;  //G的邻接矩阵Vector表示
typedef std::vector<int> OFFSET_VECTOR;

typedef ADJPOINTSSET VERTEXCOVER;

#endif // COMMONDATASTRUCTURE_H

#ifndef CPRECISETIMER_H
#define CPRECISETIMER_H

#include <windows.h>

class CPreciseTimer
{
public:
    CPreciseTimer();

    bool SupportsHighResCounter();
    void StartTimer();
    void StopTimer();
    __int64 GetTime();

private:
    //Auxiliary Function
    void UpdateElapsed();

    //Member variables
    bool m_bRunning;
    __int64 m_i64Start;
    __int64 m_i64Elapsed;

    //Some auxiliary variables
    __int64 m_i64Counts;
    LARGE_INTEGER m_liCount;

    //Static Variables
    static bool sm_bInit;
    static bool sm_bPerformanceCounter;
    static __int64 sm_i64Freq;
};

inline bool CPreciseTimer::SupportsHighResCounter()
{
    return sm_bPerformanceCounter;
}

//Auxiliary Function
inline void CPreciseTimer::UpdateElapsed()
{
    if(true == sm_bPerformanceCounter)
    {
        QueryPerformanceCounter(&m_liCount);
        m_i64Counts = ((__int64)m_liCount.HighPart << 32) + (__int64)m_liCount.LowPart;
        //Transform in microseconds
        (m_i64Counts *= 1000000) /= sm_i64Freq;
    }
    else
        //Transform milliseconds to microseconds
        m_i64Counts = (__int64)GetTickCount() * 1000;
    if(m_i64Counts > m_i64Start)
        m_i64Elapsed = m_i64Counts - m_i64Start;
    else
        //Eliminate possible number overflow (0x7fffffffffffffff is the maximal __int64 positive number)
        m_i64Elapsed = (0x7fffffffffffffff - m_i64Start) + m_i64Counts;
}

#endif // CPRECISETIMER_H

#include "cprecisetimer.h"

bool CPreciseTimer::sm_bInit = false;
bool CPreciseTimer::sm_bPerformanceCounter;
__int64 CPreciseTimer::sm_i64Freq;

//CONSTRUCTOR
CPreciseTimer::CPreciseTimer() : m_i64Start(0), m_i64Elapsed(0), m_bRunning(false)
{
    //Only if not already initialized
    if(false == sm_bInit)
    {
        //Initializing some static variables dependent on the system just once
        LARGE_INTEGER liFreq