字符串的排列组合问题

#include <string>
#include <iostream>
using namespace std;

void permulation_solution1(char *pStr, int begin, int end)
{
	if (begin == end - 1)
		cout<<pStr<<endl;
	else
	{
		for (int i = begin; i < end; i++)
		{
			swap(pStr[i], pStr[begin]);
			permulation_solution1(pStr, begin+1, end);
			swap(pStr[i], pStr[begin]);
		}
	}
}

int main()
{
	char pStr[] = "abcd";
	permulation_solution1(pStr, 0 , 4);
}

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

void combination_m(char *pStr, int m, vector<char> &result)
{
	if (pStr == NULL || (*pStr == '\0' && m != 0))
		return ;
	if (m == 0)
	{
		for (vector<char>::iterator it = result.begin(); it != result.end(); it++)
		{
			cout<<*it<<" ";
		}
		cout<<endl;
		return;
	}

	result.push_back(*pStr);
	combination_m(pStr+1, m-1, result);
	result.pop_back();
	combination_m(pStr+1, m, result);
}

void combinnation(char *pStr)
{
	if (pStr == NULL || *pStr == '\0')
	{
		return;
	}
	int number = strlen(pStr);
	for (int i = 1; i <= number; i++)
	{
		vector<char> result;
		combination_m(pStr, i, result);
	}
}

int main()
{
	char pStr[] = "abc";
	combinnation(pStr);
}

/函数功能 ： 求解number次打中sum环的种数
//函数参数 ： number为打靶次数，sum为需要命中的环数，result用来保存中间结果，total记录种数 
//返回值 ：   无

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

void shootProblem_Solution1(int number, int sum, vector<int> &result, int* total)//此处total传递的应该为指针！
{
	if (sum < 0 || number*10 < sum)
		return;
	if (number == 1)
	{
		if (sum <= 10)
		{
			for (vector<int>::iterator it = result.begin(); it < result.end(); it++)
			{
				cout<<*it<<" ";
			}
			cout<<sum<<endl;
			(*total)++;
		}
		else
			return;
	}
	for (int i = 0; i <= 10; i++)
	{
		result.push_back(i);
		shootProblem_Solution1(number-1, sum-i, result, total);
		result.pop_back();
	}
}

void shootProblem(int number, int sum)
{
	int total = 0;
	vector<int> result;
	shootProblem_Solution1(number, sum, result, &total);
	cout<<"total sum="<<total<<endl;
}

int main()
{
	shootProblem(10,90);
}