vector<string> letterCombinations(string digits) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
vector<char> charmap[10];
vector<string> result;
for(int i= 'a'; i< 's'; i++)
{
charmap[ (i - 'a') / 3 + 2].push_back(i);
}
charmap[7].push_back('s');
charmap[8].push_back('t');
charmap[8].push_back('u');
charmap[8].push_back('v');
charmap[9].push_back('w');
charmap[9].push_back('x');
charmap[9].push_back('y');
charmap[9].push_back('z');
charmap[0].push_back(' ');
findCombinations(digits, 0, digits.length() - 1, charmap, "", result);
return result;
}
void findCombinations(string digits, int start, int end, vector<char> charmap[10], string substring, vector<string> &result)
{
if(start > end)
{
result.push_back(substring);
return;
}
char digit = digits.at(start);
if(digit == '1')
return findCombinations(digits, start + 1, end, charmap, substring, result);
for(int i = 0; i<charmap[digit - '0'].size(); i++)
{
int digit_int = (digit - '0');
substring.push_back(charmap[digit_int][i]);
findCombinations(digits, start + 1, end, charmap, substring, result);
substring.erase(substring.length() - 1);
}
}
int main(){
int totalAmount = 200;
std::vector<int> denominations;
denominations.push_back(1);
denominations.push_back(2);
denominations.push_back(5);
denominations.push_back(10);
denominations.push_back(20);
denominations.push_back(50);
denominations.push_back(100);
denominations.push_back(200);
int result = findCombinations(totalAmount, denominations);
printf("Number of Combinations: %i\n", result);
}
int findCombinations(int amount, std::vector<int> denominations)
{
int totalCombinations = 0;
int coinValue = denominations.back();
printf("Value: %i Amount: %i\n",coinValue, amount);
int numCoins = amount / coinValue;
int remaining = amount%coinValue;
if(denominations.size() == 0 || (denominations.size() == 1 && remaining == 0))
{
printf("HERE: Value: %i Amount: %i\n",coinValue, amount);
return 1;
}
else
{
denominations.pop_back();
for(int i = numCoins; i >= 0 ; i--)
{
int thisRemainder = amount - i*coinValue;
totalCombinations += findCombinations(thisRemainder, denominations);
}
}
return totalCombinations;
}