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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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168
16-slices/exercises/26-print-daily-requests/main.go
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@ -1,16 +1,18 @@
package main package main
import (
"fmt"
"strings"
)
// --------------------------------------------------------- // ---------------------------------------------------------
// EXERCISE: Print daily requests // EXERCISE: Print daily requests
// //
// You've got a requests log for a system in a slice: `reqs`. // You've got request logs of a web server. The log data
// The log contains the total request counts per 8 hours. // 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 // See the `reqs` slice and the steps in the code below.
// to group the requests daily into a slice named: `daily`.
//
// Please follow the instructions inside the code to solve
// the exercise.
// //
// //
// EXPECTED OUTPUT // EXPECTED OUTPUT
@ -23,87 +25,77 @@ package main
// --------------------------------------------------------- // ---------------------------------------------------------
func main() { func main() {
// // ================================================
// #1: DAILY REQUESTS DATA // Don't touch this code.
//
// . 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
//
// reqs := []int{ // There are 3 request totals per day (8-hourly)
// // 1st day const N = 3
// 500, 600, 250,
// // 2nd day
// 200, 400, 50,
// // 3rd day
// 900, 800, 600,
// // 4th day
// 750, 250, 100,
// // last day
// 100, 150,
// }
// // DAILY REQUESTS DATA (8-HOURLY TOTALS PER DAY)
// #2: Group the `reqs` per day into a slice named: `daily` reqs := []int{
// 500, 600, 250, // 1st day: 1350 requests
// . Create the daily slice using the `make` function 200, 400, 50, // 2nd day: 650 requests
// 900, 800, 600, // 3rd day: 2300 requests
// . Anticipate the length argument to the make function using this data: 750, 250, 100, // 4th day: 1100 requests
// // grand total: 5400 requests
// + The length of the reqs slice }
// + There are 3 requests totals per day // ================================================
// + There are residual elements (the last day)
// _ = reqs // remove this when you start
// ! So, do not blindly allocate a slice.
// // ================================================
// ! Allocate the slice efficiently with the exact size needed. // Allocate a slice efficiently with the exact size needed.
// //
// . Then append to it the daily requests in a "loop" // Find the `size` automatically using the `reqs` slice.
// // Do not type it manually.
//
// // Change this code:
// #3: Print the header: size := 0 // you need to find the size.
// daily := make([][]int, 0, size)
// Day Requests //
// ==================== // ================================================
//
// ================================================
// // Group the `reqs` per day into the slice: `daily`.
// #4: Print the data per day along with the totals: //
// // So the daily will be:
// 1 500 // [
// 1 600 // [500, 600, 250]
// 1 250 // [200, 400, 50]
// -------------------- // [900, 800, 600]
// 1350 --> Print the daily total requests // [750, 250, 100]
// // ]
// 2 200 //
// 2 400 // Change this code:
// 2 50 //
// -------------------- // for N < len(reqs) {
// 650 // append the daily requests to `daily` per 8-hour groups
// // }
// 2000 --> Also print the grand total // ================================================
// ------------------------------------------------------------------------ // ================================================
// // Don't touch the following code:
// ❤️ NOTE ❤️
// // Print the header
// If you could't solve this challenge, please do not get discouraged. fmt.Printf("%-10s%-10s\n", "Day", "Requests")
// fmt.Println(strings.Repeat("=", 20))
// Look at the solution, then try to solve it again. This is valuable too.
// // Print the data per day along with the totals
// Then ️change the request data, the number of requests per day (now it's 3), var grand int
// 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
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@ -13,24 +13,22 @@ import (
) )
func main() { func main() {
// // There are 3 request totals per day
// 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
//
const N = 3 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) l := len(reqs)
size := l / N size := l / N
@ -38,44 +36,49 @@ func main() {
size++ size++
} }
daily := make([][]int, 0, 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) { for N <= len(reqs) {
daily = append(daily, reqs[:N]) // add the current batch of nums to the `groups` daily = append(daily, reqs[:N]) // append the daily requests
reqs = reqs[N:] // move the slice pointer for the next batch reqs = reqs[N:] // move the slice pointer for the next day
} }
// ================================================
// // ================================================
// Add the residual elements to the group (len(reqs) % N) // Don't touch the following code:
//
daily = append(daily, reqs)
// // Print the header
// Print the header:
//
fmt.Printf("%-10s%-10s\n", "Day", "Requests") fmt.Printf("%-10s%-10s\n", "Day", "Requests")
fmt.Println(strings.Repeat("=", 20)) 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 var grand int
for i, d := range daily { for i, day := range daily {
var sum int var sum int
for _, q := range d { for _, req := range day {
sum += q sum += req
fmt.Printf("%-10d%-10d\n", i+1, q) fmt.Printf("%-10d%-10d\n", i+1, req)
} }
fmt.Println(strings.Repeat("-", 20)) fmt.Printf("%9s %-10d\n\n", "TOTAL:", sum)
fmt.Printf("%10s%-10d\n\n", "", sum)
grand += sum grand += sum
} }
fmt.Printf("%10s%-10d\n", "", grand) fmt.Printf("%9s %-10d\n", "GRAND:", grand)
// ================================================
} }