Help about strings and vectors exercises

[snowden19]

Hello everyone ,
I need a little help about string and vectors exercises..
I have few tasks.

1. Write a function or functions that allows the user to choose among many options for making calculations related to
square matrices. The limits are 10 by 10 arrays and functions should be able to give the user the following:
a. Enter a matrix as a 2D array.
b. Summation of each column.
c. Summation of each row.
d. Summation of diagonal.
e. Summation of off diagonal.
f. Summation of certain column.
g. Summation of certain row.

2. Write a c++ program that allows the user to enter a name and a password and store them in 2 arrays or vectors.

3. After having the lists of users and passwords, write a function that checks if the user on the list or not, and if he or
she on the list, if his password is correct or not. Use search functions because the if else, or switch is not practical
when you have lists of 100 or 1000 users.

[nuderobmonkey]

It would be the best if you use the search bar at top and look for std::string, std::vector and std::array, and find out what methods they provide. For std::vector, the almost important methods are size(), [ ] and push_back.

Here a hint how to instantiate a two-dimensional matrix with std::array:

int size;
...
std::array< std::array<int,size>,size > arr;

Consider that the cells of such an array are containing arbitrary values if they aren't initialized.

[gunnerfunner]

store them in 2 arrays or vectors

since you have this choice ( a lot of folks who post here don't, their teachers force them to use C-style arrays) suggest going with std::vector -
http://stackoverflow.com/questions/6632971/what-is-the-difference-between-stdarray-and-stdvector-when-do-you-use-one-o
http://stackoverflow.com/questions/4424579/stdvector-versus-stdarray-in-c