I have so much trouble with this questions not only questions I want to study big o and time complexity but until now I didn’t found any good sit that explained it so could anyone help me by proved some sits about big o and time complexity and I really need help to solve thes questions cuz I don’t know how to calculate time complexity and big O could anyone help me with the answer and the Explanation please

These are the questions

algorithm to print the m smallest elements in an array of size n. Find its time complexity in terms of m and n.

algorithm that prints all possible subsets of three elements among a set of n elements. Find the time complexity of your program.

Show that n2 + 3 n 3 O(n3).

5n5+4n4+6n3+2n2+n+7 O(n5).

Sort functions in decreasing complexity order:

nLn n ; (lg n)2; 5n2 + 7 n ; n 5/2 ; n! ; 2n! ; 4n; nn; nn + Ln n;

5 log n; sqrt(n); en; 8n+12; 10n+n20.

Find the time complexity of the following programs :

(a) for (i=7;i<=(7+n) ; i++)

x=x+p;

(b) for (i=1;i<=66;i++)

for (j=1;j<=n; j++)

A*[j]=1;*

(c) for (i=1;i<=n;i++)

for (j=1;j<=i;j++)

y=y+n;

(d) for (i=1;i<=n;i++)

for (j=1;i<=n; j++)

for (k=1, k<=n; k++)

C*[j] = C [j]+A[k]*B[k][j];*

(e) Assume that n is a power of 2, find the time complexity of the following program:

i=1;

while (i<=n)

{ for (j=1;j<=n;j++) cout<<”1”;

i=i*2;

};

I really need the answer and the Explanation as soon as possible