怎么用C语言进行排列？比如，1到6 六个数，输出所有可能的组合

Answer 1

刚回答了一个组合的，现在是排列的。方法类似，采用递归方法。

void CopyArrayWithExcept(int a[], int nCount, int b[], int nExcept)
{
for(int i=0, j=0; i<nCount; i++)
{
if(i != nExcept)
{
b[j++] = a[i];
}
}
}

int g_nPrintCount = 0; //为了控制每行输出10个
int ArrangeAll(int a[], int nCount, char* szPre)
{
if(nCount == 1)
{
printf("%s%d ", szPre, a[0] );
if( (++g_nPrintCount%10==0))
{
printf("\n");
}
return 1;
}
else
{
int nTotal=0;
for(int i=0; i<nCount; i++)
{
char szBuf[10] ={0};
int *pNum = new int[nCount-1];

sprintf(szBuf, "%s%d", szPre, a[i]);
CopyArrayWithExcept(a, nCount, pNum, i);

nTotal += ArrangeAll(pNum, nCount-1, szBuf);

delete[] pNum;
}

return nTotal;
}

}

int main()
{
int a[] = {1,2,3,4,5,6};
int nTotal = ArrangeAll(a, sizeof(a)/sizeof(a[0]), "");
printf("\nTotal Count=%d\n", nTotal);
return 1;
}