Time Complexity of the C program

Question

What will be the time complexity of the following function? is it O(n^3) or O(n^4)?

i am getting O(n^3) in the first for loop, it will undergo n times. in the second for loop, for every nth element it will go n^2 times, therefore the total complexity till here is O(n^3) now, the if statement will only hold true value only for n out of n^2 values, and for every n values the k- for loop will go till n^2 elements and hence the complexity is O(n^3). I have taken few values of n: for n=3 ,c=25

for n=10,c=1705

for n=50,c=834275

for(i=1;i<=n;++i)                            
    for(j=1;j<=(i*i);++j)  
        if((j%i)==0)                               
            for(k=1;k<=j;++k)      
                c=c+1;

Answer 1

这种程序的时间复杂度是O(n^3)量级。