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refactor: slices 26th exercise

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This commit is contained in:
Inanc Gumus
2019-08-18 14:43:37 +03:00
parent 552a6a6cf7
commit 55419e59b7
2 changed files with 115 additions and 120 deletions
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160
16-slices/exercises/26-print-daily-requests/main.go
View File

@ -1,16 +1,18 @@
package main
import (
"fmt"
"strings"
)
// ---------------------------------------------------------
// EXERCISE: Print daily requests
//
// You've got a requests log for a system in a slice: `reqs`.
// The log contains the total request counts per 8 hours.
// You've got request logs of a web server. The log data
// contains 8-hourly totals per each day. Find and print
// the total requests per day, as well as the grand total.
//
// The reqs slice is a single-dimensional slice but you need
// to group the requests daily into a slice named: `daily`.
//
// Please follow the instructions inside the code to solve
// the exercise.
// See the `reqs` slice and the steps in the code below.
//
//
// EXPECTED OUTPUT
@ -23,87 +25,77 @@ package main
// ---------------------------------------------------------
func main() {
//
// #1: DAILY REQUESTS DATA
//
// . The system collects and groups the requests per 8 hours
//
// . So there are 3 requests totals per day
//
// . Your code should be robust enough to work with
// insufficient data. For example, in the last day
// there are only two request totals: 100 and 150.
//
// So, don't forget to handle that edge case as well.
//
// . Uncomment the code below and start
//
// ================================================
// Don't touch this code.
// reqs := []int{
// // 1st day
// 500, 600, 250,
// // 2nd day
// 200, 400, 50,
// // 3rd day
// 900, 800, 600,
// // 4th day
// 750, 250, 100,
// // last day
// 100, 150,
// There are 3 request totals per day (8-hourly)
const N = 3
// DAILY REQUESTS DATA (8-HOURLY TOTALS PER DAY)
reqs := []int{
500, 600, 250, // 1st day: 1350 requests
200, 400, 50, // 2nd day: 650 requests
900, 800, 600, // 3rd day: 2300 requests
750, 250, 100, // 4th day: 1100 requests
// grand total: 5400 requests
}
// ================================================
_ = reqs // remove this when you start
// ================================================
// Allocate a slice efficiently with the exact size needed.
//
// Find the `size` automatically using the `reqs` slice.
// Do not type it manually.
//
// Change this code:
size := 0 // you need to find the size.
daily := make([][]int, 0, size)
//
// ================================================
// ================================================
// Group the `reqs` per day into the slice: `daily`.
//
// So the daily will be:
// [
// [500, 600, 250]
// [200, 400, 50]
// [900, 800, 600]
// [750, 250, 100]
// ]
//
// Change this code:
//
// for N < len(reqs) {
// append the daily requests to `daily` per 8-hour groups
// }
// ================================================
//
// #2: Group the `reqs` per day into a slice named: `daily`
//
// . Create the daily slice using the `make` function
//
// . Anticipate the length argument to the make function using this data:
//
// + The length of the reqs slice
// + There are 3 requests totals per day
// + There are residual elements (the last day)
//
// ! So, do not blindly allocate a slice.
//
// ! Allocate the slice efficiently with the exact size needed.
//
// . Then append to it the daily requests in a "loop"
//
// ================================================
// Don't touch the following code:
//
// #3: Print the header:
//
// Day Requests
// ====================
//
// Print the header
fmt.Printf("%-10s%-10s\n", "Day", "Requests")
fmt.Println(strings.Repeat("=", 20))
//
// #4: Print the data per day along with the totals:
//
// 1 500
// 1 600
// 1 250
// --------------------
// 1350 --> Print the daily total requests
//
// 2 200
// 2 400
// 2 50
// --------------------
// 650
//
// 2000 --> Also print the grand total
// Print the data per day along with the totals
var grand int
// ------------------------------------------------------------------------
//
// ❤️ NOTE ❤️
//
// If you could't solve this challenge, please do not get discouraged.
//
// Look at the solution, then try to solve it again. This is valuable too.
//
// Then ️change the request data, the number of requests per day (now it's 3),
// etc., and then try to solve it again.
//
// ------------------------------------------------------------------------
for i, day := range daily {
var sum int
for _, req := range day {
sum += req
fmt.Printf("%-10d%-10d\n", i+1, req)
}
fmt.Printf("%9s %-10d\n\n", "TOTAL:", sum)
grand += sum
}
fmt.Printf("%9s %-10d\n", "GRAND:", grand)
// ================================================
}

75
16-slices/exercises/26-print-daily-requests/solution/main.go
View File

@ -13,24 +13,22 @@ import (
)
func main() {
//
// DAILY REQUESTS DATA
//
reqs := []int{
500, 600, 250,
200, 400, 50,
900, 800, 600,
750, 250, 100,
100, 150,
}
//
// There are 3 requests per day
//
// There are 3 request totals per day
const N = 3
// DAILY REQUESTS DATA (PER 8-HOUR)
reqs := []int{
500, 600, 250, // 1st day
200, 400, 50, // 2nd day
900, 800, 600, // 3rd day
750, 250, 100, // 4th day
}
// ================================================
// Allocate a slice efficiently with the exact size needed.
//
// Allocate the slice efficiently with the exact size needed
// Find the `size` automatically using the `reqs` slice.
// Do not type it manually.
//
l := len(reqs)
size := l / N
@ -38,44 +36,49 @@ func main() {
size++
}
daily := make([][]int, 0, size)
//
// ================================================
// ================================================
// Group the `reqs` per day into the slice: `daily`.
//
// Group the `reqs` per day into a slice named: `daily`
// So the daily will be:
// [
// [500, 600, 250]
// [200, 400, 50]
// [900, 800, 600]
// [750, 250, 100]
// ]
//
for N < len(reqs) {
daily = append(daily, reqs[:N]) // add the current batch of nums to the `groups`
reqs = reqs[N:] // move the slice pointer for the next batch
for N <= len(reqs) {
daily = append(daily, reqs[:N]) // append the daily requests
reqs = reqs[N:] // move the slice pointer for the next day
}
// ================================================
//
// Add the residual elements to the group (len(reqs) % N)
//
daily = append(daily, reqs)
// ================================================
// Don't touch the following code:
//
// Print the header:
//
// Print the header
fmt.Printf("%-10s%-10s\n", "Day", "Requests")
fmt.Println(strings.Repeat("=", 20))
//
// Print the data per day along with the totals:
//
// Print the data per day along with the totals
var grand int
for i, d := range daily {
for i, day := range daily {
var sum int
for _, q := range d {
sum += q
fmt.Printf("%-10d%-10d\n", i+1, q)
for _, req := range day {
sum += req
fmt.Printf("%-10d%-10d\n", i+1, req)
}
fmt.Println(strings.Repeat("-", 20))
fmt.Printf("%10s%-10d\n\n", "", sum)
fmt.Printf("%9s %-10d\n\n", "TOTAL:", sum)
grand += sum
}
fmt.Printf("%10s%-10d\n", "", grand)
fmt.Printf("%9s %-10d\n", "GRAND:", grand)
// ================================================
}