// Return the number of ways that all n2 elements of a2 appear
// in the n1 element array a1 in the same order (though not
// necessarily consecutively). The empty sequence appears in a
// sequence of length n1 in 1 way, even if n1 is 0.
// For example, if a1 is the 7 element array
// 10 50 40 20 50 40 30
// then for this value of a2 the function must return
// 10 20 40 1
// 10 40 30 2
// 20 10 40 0
// 50 40 30 3
int countIncludes(const double a1[], int n1, const double a2[], int n2)
{
if(n2 == 0) return 1;
if(n2 > n1) return 0;
if(a1[0] != a2[0]) return countIncludes(a1+1, n1-1, a2, n2);
else return countIncludes(a1+1, n1-1, a2+1, n2-1) + countIncludes(a1+1, n1-1, a2, n2);
}
// Return the number of ways that all n2 elements of a2 appear
// in the n1 element array a1 in the same order (though not
// necessarily consecutively). The empty sequence appears in a
// sequence of length n1 in 1 way, even if n1 is 0.
// For example, if a1 is the 7 element array
// 10 50 40 20 50 40 30
// then for this value of a2 the function must return
// 10 20 40 1
// 10 40 30 2
// 20 10 40 0
// 50 40 30 3
int countIncludes(const double a1[], int n1, const double a2[], int n2)
{
int count = 0;
if (n2 <=0)
return 1;
if (n1 <= 0)
return 0;
if (n1 < n2)
return 0;
if (a2[0] != a1[0])
return countIncludes(a1+1, n1-1, a2, n2);
else
{
//if a match is found, move on to next element of a2
int next = countIncludes(a1+1, n1-1, a2+1, n2-1);
//but also continue checking through a1 for same match
int same = countIncludes(a1+1, n1-1, a2, n2);
return same+next;
}
}
int countIncludes(const char a1[], int n1, const char a2[], int n2)
{
if (n2<1)
{
return 1;
}
if (n1 < 1)
{
return 0;
}
if (a1[0] == a2[0])
{
return countIncludes(a1 + 1, n1 - 1, a2 + 1, n2 - 1)+countIncludes(a1 + 1, n1 - 1, a2, n2);
}
else{
return countIncludes(a1 + 1, n1-1, a2, n2);
}
}
