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CISC2000: Computer Science II - InflationRate Part3
InflationRate Part3 is going to calculate the median inflation rate, using arrays and sorting.
Start with the code from InflationRate Part2.
Example: cp InflationRate2.cpp InflationRate3.cpp
This lab is designed to provide practice of functions, call-by-reference parameters, step-wise refinement, partially filled arrays, and sorting.
Objective:
We are going to add code to calculate the Median Rate of inflation.
The median is the middle entry, where half are higher, half are lower.
If there is an odd number of elements, this is easy.
If there is an even number, we average the middle two.
However, the array must be sorted.
You might wish to print the array to be sure it is sorted. This is not part of the autograded output.
Directions
Do each part, one at a time.
- Build getPCIValues
If you have not already done it, make a function called getCPIValues to read in the two CPI values (both floats). If either value is invalid, give an error:
"Error: CPI values must be greater than 0."
…. and request new values.
- Create an array to accumulate the list of computed inflation rates
a. The array should hold 20 inflation rates - also floating point.
b. Add code to main that inserts the computed inflation rate into the next position in the array.
c. Declare and implement a function called swap_values that takes two float parameters.
- Add a function that sorts an array of floats. Call it sort_array
a. Declare and implement a function that uses either a selection sort or bubble sort to put the array values into ascending order (i.e. smallest to largest).
Using swap_values to sort, using one of these two methods:
Bubble Sort:
Repeatedly swap mis-ordered values until none are out of order.
Selection Sort:
For each index i= 0..N, Find the minimum value and swap it with the value at A[i].
+ Function parameters: an array of floats and an int with the number of elements ACTUALLY in the array
+ Your sort function must use the swap_values function defined above to exchange the values in the array during the sort.
Please make a function to print each inflation rate on its own line. Call it to check that your sort works.
- Add a function called findMedianRate that calculates the median inflation rate using sort_array
a. Declare and implement a function called findMedianRate that takes two parameters and returns a float which will be the median rate.
+ parameters: an array of floats and an int with the number of elements in the array (e.g. numRates).
b. Sort the array using your sort_array function defined above. Once the array is sorted, use the following logic to calculate the median value:
+ if the number of rates is odd, then it is the one in the middle.
+ if the number of rates is even, then the median rate is calculated as the average of the two rates in the middle.
Expected
Output:
Enter the old and new consumer price
indices: 272.35
276.50
Inflation rate is
1.52377
Try again? (y or n): y
Enter
the old and new consumer price indices: 276.50
280.35
Inflation rate is
1.39241
Try again? (y or n): y
Enter
the old and new consumer price indices: 280.35
285.50
Inflation rate is
1.83699
Try again? (y or n): y
Enter
the old and new consumer price indices: 285.50
290.35
Inflation rate is
1.69878
Try again? (y or n): y
Enter
the old and new consumer price indices: 290.35
294.55
Inflation rate is
1.44652
Try again? (y or n): n
Average rate is 1.57969
Median rate is 1.52377
Sorted inflation rates
1.39241
1.44652
1.52377
1.69878
1.83699
Enter the old and new consumer price
indices: 272.35
276.50
Inflation rate is
1.52377
Try again? (y or n): y
Enter
the old and new consumer price indices: 276.50
280.35
Inflation rate is
1.39241
Try again? (y or n): y
Enter
the old and new consumer price indices: 280.35
285.50
Inflation rate is
1.83699
Try again? (y or n): y
Enter
the old and new consumer price indices: 285.50
290.35
Inflation rate is
1.69878
Try again? (y or n): y
Enter
the old and new consumer price indices: 290.35
294.55
Inflation rate is
1.44652
Try again? (y or n): y
Enter
the old and new consumer price indices: 294.55
299.75
Inflation rate is
1.76541
Try again? (y or n): n
Average rate is 1.61065
Median rate
is 1.61127
Sorted inflation
rates
1.39241
1.44652
1.52377
1.69878
1.76541
1.83699
Test Case input data (you can copy & paste)
- Odd number of Inflation Rates
272.35 276.50
y
276.50
280.35
y
280.35
285.50
y
285.50 290.35
y
290.35
294.55
n
- Even number of Inflation Rates
272.35 276.50
y
276.50
280.35
y
280.35
285.50
y
285.50
290.35
y
290.35 294.55
y
294.55
299.75
n
- Some Negative CPI Values
237.844 238.323
y
-238.323 239.668
238.323 239.668
y
239.668 240.779
y
240.779 -241.645
240.779 241.645
n
- Some zero CPI values
0 239.111
239.111 0
239.111 240.222
n
