Files
learngo/16-slices/exercises/26-print-daily-requests/solution/main.go
2019-08-23 00:25:38 +03:00

102 lines
2.1 KiB
Go

// For more tutorials: https://blog.learngoprogramming.com
//
// Copyright © 2018 Inanc Gumus
// Learn Go Programming Course
// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
//
package main
import (
"fmt"
"strings"
)
func main() {
// There are 3 request totals per day
const N = 3
// DAILY REQUESTS DATA (PER 8-HOUR)
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
}
// ALSO TRY IT WITH THIS DATA:
// reqs = []int{
// 500, 600, 250,
// 200, 400, 50,
// 900, 800, 600,
// 750, 250, 100,
// 150, 654, 235,
// 320, 534, 765,
// 121, 876, 285,
// 543, 642,
// }
// ================================================
// Allocate a 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
if l%N != 0 {
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]
// ]
//
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 data
if len(reqs) > 0 {
daily = append(daily, reqs)
}
// ================================================
// ================================================
// Print the header
fmt.Printf("%-10s%-10s\n", "Day", "Requests")
fmt.Println(strings.Repeat("=", 20))
// Print the data per day along with the totals
var grand int
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)
// ================================================
}