Accessing the value of the last iteration from inside the loop - c++

Question

I know this might be just an if statement that i don't know where to place but i am having difficulties understanding how to proceed.
#include <time.h>
#include <iostream>
#include <sstream>
using namespace std;
int main()
{
float a;
float sum;
float tA = 5050 ;
int b [5] = {5, 10, 15, 30, 100};
double bin;
double divident;
cout<<"Random numbers generated between 0 and 1:"<<endl;
srand( (unsigned)time( NULL ) );
for (int i = 0; i < 5; i++)
{
a = (float) rand()/RAND_MAX;
sum += a;
cout << a << "\t Total: " << sum << "\t Bin: " << a* divident << endl;
}
cout << "Total of Random Numbers: " << sum << endl;
divident = tA/sum;
cout <<"Divident: "<< divident << endl;
cout <<"Last a: "<< a << endl;
return 0;
}
OUTPUT:
Random numbers generated between 0 and 1:
0.228659 Total: 0.228659 Bin: 0
0.337218 Total: 0.565877 Bin: 0
0.955376 Total: 1.52125 Bin: 0
0.356451 Total: 1.8777 Bin: 0
0.7963 Total: 2.674 Bin: 0
Total of Random Numbers: 2.674
Divident: 1888.55
Last a: 0.7963
The dividend should be a variable (tA)/the sum of all 5 random generated numbers (2.674) and every random value of 'a' be multiplied by it on every row (inside bin column). But I do not know exactly how to access it since in the code it is the last iteration of 'sum'
as you can see my next step is to place all five values into a designated array bin *int b[5](labeled 5, 10, 15, 30, 100). and eventually multiply the expected frequency in every bin with the bin label(5,10,15.. 1000) I'm thinking std map or something similar, so any advanced std solutions or pointers (sic) on how to proceed further would greatly be appreciated.

Answer 1

You can only compute divident after the end of the loop, but you want to use it starting with the first iteration: that is not possible using one single loop. You should use two loops, first one to compute sum and divident, and second one to display the values:
float sum = 0;
...
double arr[5];
for (int i = 0; i < 5; i++)
{
a = (float)rand() / RAND_MAX;
sum += a;
arr[i] = a;
}
divident = tA / sum;
for (int i = 0; i < 5; i++)
{
a = arr[i];
cout << a << "\t Total: " << sum << "\t Bin: " << a * divident << endl;
}