```
int nthUglyNumber(int n) {
int* uglyNums = (int*)malloc(n * sizeof(int));
uglyNums[0] = 1;
int index2 = 0, index3 = 0, index5 = 0;
int factor2 = 2, factor3 = 3, factor5 = 5;
for(int i = 1; i < n; i++)
{
int temp = factor2 < factor3 ? factor2 : factor3;
int min = temp < factor5 ? temp : factor5;
uglyNums[i] = min;
if(min == factor2)
{
factor2 = 2 * uglyNums[++index2];
}
if(min == factor3)
{
factor3 = 3 * uglyNums[++index3];
}
if(min == factor5)
{
factor5 = 5 * uglyNums[++index5];
}
}
return uglyNums[n-1];
}
```