动态规划___数学三角形问题

从文本input,txt输入 将结果输出到output.txt

//类里有递归和迭代两种版本
#include<iostream>

#include <fstream.h>

#define MIN_NUM -99999

#define max(a, b) (a>b?a:b)

class NumTrigon

{

public:

NumTrigon(const char* filename)

{

m_triSize = 0;

m_pTrigon = NULL;

m_MaxSum = 0;

GetDateFromFile(filename);

InitMemo();

}

void GetDateFromFile(const char* datefile)

//从文件中读取数据到m_pTrigon

{

ifstream readfile(datefile);

readfile>>m_triSize;

m_pTrigon = new int*[m_triSize];

for(int i=0; i<m_triSize; i++)

m_pTrigon[i] = new int[m_triSize];

//注意读取顺序为m_pTrigon[j][i]

for(i=0; i<m_triSize; i++)

for (int j=0; j<=i; j++)

readfile>>m_pTrigon[j][i];

readfile.close();

}

void InitMemo()

//根据m_triSize的值分配并初始化Memo为最小

{

m_pMemo = new int*[m_triSize];

for(int i=0; i<m_triSize; i++)

m_pMemo[i] = new int[m_triSize];

for(i=0; i<m_triSize; i++)

for(int j=0; j<m_triSize; j++)

m_pMemo[i][j] = MIN_NUM;

}

int GetMaxSum(int i, int j)
//递归版

{

//判断有无最优解的记录

if(m_pMemo[i][j] != MIN_NUM)

return m_pMemo[i][j];



int n = m_pTrigon[i][j];

//递归终止条件 即列数到了最后

if(j == m_triSize-1)

{

m_pMemo[i][j] = n;

return n;

}

//递归求解 并在返回时记录最优解

m_pMemo[i][j] = max(n+GetMaxSum(i, j+1), n+GetMaxSum(i+1, j+1));

return m_pMemo[i][j];

}

void CalcuMaxSum()

{

m_MaxSum = GetMaxSum(0,0);

}

void CalcuMaxSum_Loop()

//迭代版

{

//初始化最底层子问题Memo

for(int i=0; i<m_triSize; i++)

m_pMemo[i][m_triSize-1] = m_pTrigon[i][m_triSize-1];

//逐层向上求解

for(int j=m_triSize-2; j>=0; j--)

for (int i=0; i<=j; i++)

m_pMemo[i][j] = m_pTrigon[i][j] + max(m_pMemo[i][j+1], m_pMemo[i+1][j+1]);

m_MaxSum = m_pMemo[0][0];

}

void WriteSumToFile(const char* aimfile)

{

ofstream writefile(aimfile);

writefile<<m_MaxSum;

writefile.close();

}

~NumTrigon()

{

for(int i=0; i<m_triSize; i++)

{

delete m_pTrigon[i];

delete m_pMemo[i];

}

delete m_pTrigon;

delete m_pMemo;



}

private:

int m_triSize;

int** m_pTrigon;

int m_MaxSum;

int** m_pMemo;

};

int main()

{

NumTrigon test("input.txt");

test.CalcuMaxSum_Loop();

test.WriteSumToFile("output.txt");

return 0;

}