Project Euler task 38

Take the number 192 and multiply it by each of 1, 2, and 3:

192 1 = 192
192 2 = 384
192 3 = 576

By concatenating each product we get the 1 to 9 pandigital, 192384576. We will call 192384576 the concatenated product of 192 and (1,2,3)

The same can be achieved by starting with 9 and multiplying by 1, 2, 3, 4, and 5, giving the pandigital, 918273645, which is the concatenated product of 9 and (1,2,3,4,5).

What is the largest 1 to 9 pandigital 9-digit number that can be formed as the concatenated product of an integer with (1,2, ... , n) where n 1?

---------------------------------------------------------------

#include < iostream >

using namespace std;

typedef unsigned long long int uint64;

typedef unsigned short int uint16;

const uint64 lMax = 10000;

const uint64 lMin = 2;

int getLength(uint64 _n) {

int iLength = 0;

while (_n) {

iLength++;

_n /= 10;

}

return iLength;

}

uint16 setBits(uint64 _n) {

uint16 uiRes = 0;

while (_n) {

if ((_n % 10) == 0) {

_n /= 10;

continue;

}

uiRes ^= 1 << ((_n % 10) - 1);

_n /= 10;

}

return uiRes;

}

int main() {

int a = 0;

for (uint64 i = lMin; i < lMax; i++) {

int nSum = 0;

int iMult = 1;

uint16 iRes = 0;

while (nSum < 9) {

uint64 uiNum = i * iMult;

iRes ^= setBits(uiNum);

nSum += getLength(uiNum);

iMult++;

}

int nTotal = 0;

if (nSum == 9 && iRes == 0x01FF) {

for (int m = 1; m < iMult; m++)

cout << i * m;

cout << endl;

}

}

return 0;

}