Currently has an array of letters: A, D, F, Z, K, L, O], to find out all of its subsets, such as the subset have [A], [A, D], [Z,
L, O], [D, F, K, O], etc., please use the back in the search algorithm, according to the required output:
Length of 0 subset are: 1
Length of 1 subsets are: 7
Length is a subset of the 2:21
Length is 3 a subset of the...
...
Length is 6 subset are: 7
Length is 7 subset are: 1

CodePudding user response:

 # include & lt; Vector> 
# include & lt; Iostream> 

Void BackTrackSubArrays (STD: : vector & VecTemp, size_t & amp; NCount, size_t nTotal, size_t nBegin, const STD: : vector & VecArray) 
{
If (vecTemp. The size ()==nTotal) 
{
+ + nCount; 
return; 
} 

For (size_t I=nBegin; I & lt; VecArray. The size (); I++) 
{
VecTemp. Push_back (vecArray [I]); 
BackTrackSubArrays (vecTemp, nCount nTotal, I + 1, vecArray); 
VecTemp. Pop_back (); 
} 
} 

Void SubArrays (const STD: : vector & VecArray) 
{
STD: : vector VecTemp; 
VecTemp. Reserve (vecArray. The size ()); 
Size_t nCount=0; 
For (size_t I=0; I & lt;=vecArray. The size (); I++) 
{
BackTrackSubArrays (vecTemp, nCount, I, 0, vecArray); 
STD: : cout & lt; <"Length" & lt; NCount=0; 
} 
} 

Int main () 
{
SubArrays ({' A ', 'D', 'F' and 'Z', 'K', 'L', 'O'});//use c + + 11 initializes the syntax here, if the compiler doesn't support c + + 11, please your STD: : vector Enter 
system("pause"); 
return 0; 
}