Ok, looks like in my case the format of input data in tests #2 and #6 is differ from the one in the example. Accepted Go code is:


package main

import (
    "fmt"
    "sort"
)

type city struct {
    n, x, y int
}

func main() {
    var n int
    fmt.Scan(&n)
    m := make([]city, n)

    for i := 0; i < n; i++ {
        m[i].n = i + 1
        fmt.Scan(&m[i].x, &m[i].y)
    }

    sort.Slice(m, func(i, j int) bool {
        if m[i].x < m[j].x {
            return true
        }
        return false
    })

        for i := 0; i < n; i += 2 {
        fmt.Println(m[i].n, m[i+1].n)
    }
}


time:   0.14
memory: 2 044 КB


Edited by author 29.09.2020 01:10