C/C++ :: Same Random Numbers Being Created Every Time Loop Goes Around

one of my project involves loop inside loops and creating random numbers. Here is what I have so far:#include <iostream>

#include <string>
#include <cstdlib>
#include <ctime>

[Code]....

so the program will create a random value for the inflow. The idea is that the internal for loop will continue to run until the fill_level of the reservoir, which starts at 0, hits the capacity. The process of simulating how many years (each iteration of the internal for loop representing a year) is to be repeated 10 times by the parent for loop of the water_level simulation for loop.

The problem is that the random number that is supposed to created are the same number. THey are different every time I run it, but they are the same every time the loops repeat to make a new simulation.