COMP157 Fall 2007 brute force examples Sept. 17
Brute force solution to Push Button Lock:
A Test is one possible assignment of buttons combinations:
Recursively build all possible button combination assignments (including invalid ones).
Check if a button combination assignment is valid:
struct Test
{
int x[11];
int n;
Test(int _n) { n = _n; }
Test(const Test& o) { n=o.n; for (int i=0; i<o.n; i++) x[i]=o.x[i]; }
};
void make_tests(int n, int max, vector<Test>& v)
{
if (n==1)
{
for (int j=0; j<=max; j++)
{
Test t(1); t.x[0] = j;
v.push_back(t);
}
return;
}
vector<Test> v2;
make_tests(n-1,max,v2);
for (unsigned int i=0; i<v2.size(); i++)
{
Test copy(v2[i]);
copy.n++;
for (int j=0; j<=max; j++)
{
copy.x[n-1]=j;
v.push_back(copy);
}
}
}
bool checkTest(Test& test)
{
int combos[11];
int n = 0;
int i;
for (i=0; i<test.n; i++)
if (test.x[i]<test.n) { combos[n] = test.x[i]; n++; }
sort(combos, n);
if (combos[0] != 0) return false;
for (i=0; i<n-1; i++) if ((combos[i+1]-combos[i])>1) return false;
return true;
}
