Hi, I'm writing some code in C++. This code uses lists of int* that are new'd into arrays at runtime, ie std::list<int*> intList; int* someInt = new int[someSize]; intList.push_back(); After I've pushed them back, how do I access individual elements of an array? I've tried... for(std::list<int*>::iterator it = intList.begin(); it != intList.end(); ++it) { (*it)[0] = 3; } But no dice. Trying (*it) de-references it to an int*, but I don't know how to then access array elements (I tried jumping along memory using ( + x * sizeof(int)) but that didn't work either). (**it) double de-references it to an int which seems to be ok at compile time, but obviously being able to access only the first element of the array is a problem.

What do you mean "no dice"? Were you expecting there to be dice?

Quote:Original post by Winegums
Hi, I'm writing some code in C++. [...]

Take one step back and explain to us why you think you need a list of dynamically allocated arrays. Maybe then we can help.

Quote:Original post by DevFred

Quote:Original post by Winegums
Hi, I'm writing some code in C++. [...]

Take one step back and explain to us why you think you need a list of dynamically allocated arrays. Maybe then we can help.

Working on a problem posted on project euler. Problem statement is..

Quote:

By starting at the top of the triangle below and moving to
adjacent numbers on the row below,
the maximum total from top to bottom is 23.

3
7 5
2 4 6
8 5 9 3

That is, 3 + 7 + 4 + 9 = 23.

Find the maximum total from top to bottom of the triangle
below:

75
95 64
17 47 82
18 35 87 10
20 04 82 47 65
19 01 23 75 03 34
88 02 77 73 07 63 67
99 65 04 28 06 16 70 92
41 41 26 56 83 40 80 70 33
41 48 72 33 47 32 37 16 94 29
53 71 44 65 25 43 91 52 97 51 14
70 11 33 28 77 73 17 78 39 68 17 57
91 71 52 38 17 14 91 43 58 50 27 29 48
63 66 04 68 89 53 67 30 73 16 69 87 40 31
04 62 98 27 23 09 70 98 73 93 38 53 60 04 23

NOTE: As there are only 16384 routes,
it is possible to solve this problem by trying every route.
However, Problem 67, is the same challenge with a triangle containing one-hundred rows;
it cannot be solved by brute force, and requires a clever method! ;o)

I thought I'd read the data in by reading the liens in one by one, allocating an array of size (line number) and then adding that to the list. I didn't think an array would really work here, since they're constant in both dimensions.

Also, are you trying to solve the problem by bruteforce? It can easily be solved with pen and paper (and perhaps a calculator). A hint: Pick any element in the pyramid, and think about what the maximum total of the path to that element is.