POJ 1001 Exponentiation_C/C++_编程开发_程序员俱乐部

2011-11-23

高精度浮点数计算。

花了我整整一天时间才写好，POJ上给的测试数据都通过，0的1次方和1的0次方之类的输入和加入一些干扰0的输入测试也都通过，但是提交后AC不了，显示Anwser Wrong，不知道什么问题，也没找出来。崩溃了。

好好练练吧，鉴于道理已明了，先草草结贴，有时间再看。

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#include <iostream>
#include <vector>
#include <string>

using namespace std;

void getResult(vector< vector<int> >&, string, int);
void take0(string&);
void toIntVector(vector<int>&, const string&);
void mul(vector<int>&, vector<int>&);
void takeVetor0(vector<int>&);
void addDot(vector<int>&, int);

int main ()
{
    vector< vector<int> > vvResult;
    string strTmp;
    int iIndex;

    while (cin>>strTmp>>iIndex)
    {
    	getResult(vvResult, strTmp, iIndex);

    	// show result
    	string strResult = "";
    	vector< vector<int> >::iterator itervvResult = vvResult.begin();
		while (itervvResult != vvResult.end())
		{
			vector<int>::iterator iterI = (*itervvResult).begin();
			//cout << "Final viPro: ";
			while (iterI != (*itervvResult).end())
			{
				if (*iterI == 10)
				{
					strResult += ".";
				} else {
					strResult += ('0' + *iterI);
				}
				iterI++;
			}
			cout << strResult << endl;

			itervvResult++;
		}
		vvResult.clear();
    }

    return 0;
}


void getResult(vector< vector<int> >& vvResult, string strBase, int iIndex)
{
	take0(strBase);

	int iPos = -1;
	int iBase = 0;
	while (iBase < strBase.size())
	{
		if (strBase[iBase] == '.')
		{
			iPos = iBase;
		}
		iBase ++;
	}
	if (iPos == -1)
	{
		strBase += ".";
	}

	int iDotLocate = (strBase.size() - 1 - strBase.find(".")) * iIndex;
	strBase.erase(strBase.find("."), 1);

	take0(strBase);

	//cout << "take0: " << strBase << " Dot:" << iDotLocate << endl;

	vector<int> viBase;
	toIntVector(viBase, strBase);
	vector<int> viPro(viBase);

	if (iIndex == 0)
	{
		viPro.clear();
		viPro.assign(1, 1);
		vvResult.push_back(viPro);
		return;
	} else if (strBase == "0" || strBase == ".")
	{
		viPro.clear();
		vvResult.push_back(viPro);
		return;
	}

	while (--iIndex)
	{
		mul(viPro, viBase);
	}

	addDot(viPro, iDotLocate);

	vvResult.push_back(viPro);

}

void take0(string &strBase)
{
	while('0' == strBase[strBase.size() -1] && 1 != strBase.size())
	{
		strBase.erase(strBase.size() -1, 1);
	}
	while('0' == strBase[0] && 1 != strBase.size())
	{
		strBase.erase(0, 1);
	}
}

void toIntVector(vector<int>& viBase, const string& strBase)
{
	int i = 0;
	while (i < strBase.size())
	{
		viBase.push_back(strBase[i++] - '0');
	}
}

void mul(vector<int>& viPro, vector<int>& viBase)
{
	int i = 0;
	int j = 0;
	vector<int> viTmpResult(512, 0);

	// calculate
	int iCount;
	for (i = 0; i < viBase.size(); i++)
	{
		for (j = 0; j < viPro.size(); j++)
		{
			viTmpResult[i + j] += viPro[j] * viBase[i];
			iCount = i + j;
		}
	}

	viPro.clear();
	viPro.assign(512, 0);

	// handle carry
	i = i -1 + j -1;
	j = 0;
	while (i >= 0)
	{
		viPro[j] += viTmpResult[i];
		if (viPro[j] /10 > 0)
		{
			viPro[j+1] += viPro[j] / 10;
			viPro[j] %= 10;
		}

		i--;
		j++;
	}

	while (viPro[j] != 0)
	{
		viPro[j+1] += viPro[j] / 10;
		viPro[j] %= 10;

		j++;
	}

	// reverse vi
	i = 0;
	j -= 1;
	//cout <<"i, j "<< i << " "<< j-i <<endl;
	while (i < j-i)
	{
		viPro[i] = viPro[i] + viPro[j - i];
		viPro[j - i] = viPro[i] - viPro[j - i];
		viPro[i] = viPro[i] - viPro[j - i];

		i++;
	}
	//cout <<"i, j "<< i -1 << " "<< j-i +1 <<endl;

	// erase 0
	takeVetor0(viPro);

}

void takeVetor0(vector<int>& vi)
{
	vector<int>::iterator iterI = vi.end();
	iterI--;
	while (*iterI == 0)
	{
		iterI--;
	}
	iterI++;
	if (iterI != vi.end())
	{
		vi.erase(iterI, vi.end());
	}
}

void addDot(vector<int>& vi, int iDot)
{
	//cout << "iDot: " << iDot << endl;
	if (iDot == 0)
	{
		return;
	}

	vector<int>::iterator iterI = vi.begin();

	if (vi.size() < iDot)
	{
		vi.insert(iterI, iDot - vi.size(), 0);
		vi.insert(vi.begin(), 10);
	}
	else {
		vi.insert(iterI + (vi.size() - iDot), 10);
	}
}

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