Created
October 30, 2018 18:56
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| package main | |
| import ( | |
| "encoding/json" | |
| "fmt" | |
| "math/rand" | |
| "os" | |
| "sort" | |
| "time" | |
| ) | |
| type Members struct { | |
| Members []string `json:"members"` | |
| } | |
| type Group struct { | |
| Groups []Members `json:"groups"` | |
| } | |
| type Assignments struct { | |
| To string `json:"to"` | |
| From string `json:"from"` | |
| } | |
| type GroupRecord struct { | |
| Idx int | |
| Len int | |
| Members []string | |
| } | |
| type RecordsByLen []GroupRecord | |
| func (a RecordsByLen) Len() int { return len(a) } | |
| func (a RecordsByLen) Swap(i, j int) { a[i], a[j] = a[j], a[i] } | |
| func (a RecordsByLen) Less(i, j int) bool { return a[i].Len < a[j].Len } | |
| func main() { | |
| // defer profile.Start().Stop() | |
| // defer track(time.Now()) | |
| s1 := rand.NewSource(time.Now().UnixNano()) | |
| r1 := rand.New(s1) | |
| var group Group | |
| err := json.NewDecoder(os.Stdin).Decode(&group) | |
| if err != nil { | |
| fmt.Printf("error: %v\n", err) | |
| os.Exit(1) | |
| } | |
| groupIDs := make([]GroupRecord, len(group.Groups), len(group.Groups)) | |
| total := 0 | |
| for i, members := range group.Groups { | |
| groupIDs[i] = GroupRecord{ | |
| Idx: i, | |
| Len: len(members.Members), | |
| Members: members.Members, | |
| } | |
| total += groupIDs[i].Len | |
| } | |
| sort.Sort(sort.Reverse(RecordsByLen(groupIDs))) | |
| mixer := make([]int, total, total) | |
| ptr := 0 | |
| for i, g := range groupIDs { | |
| for j := 0; j < g.Len; j++ { | |
| mixer[ptr] = i | |
| ptr++ | |
| } | |
| } | |
| // fmt.Println(mixer) | |
| h1, h2 := mixer[:len(mixer)/2], mixer[len(mixer)/2:] | |
| ptr = 0 | |
| var out1, out2, out []int | |
| out1 = Interleave(h1, h2) | |
| if len(h1) == len(h2) { | |
| out2 = Interleave(h2, h1) | |
| } | |
| out = out1 | |
| if !valid(out1) { | |
| // fmt.Printf("Out1 was invalid: %v\n", out1) | |
| if !valid(out2) { | |
| fmt.Println("IT DIDN'T PAN OUT") | |
| os.Exit(1) | |
| } | |
| out = out2 | |
| } | |
| // fmt.Println(h1, h2, out) | |
| // transform out to strings | |
| names := make([]string, len(out), len(out)) | |
| for i, v := range out { | |
| record := groupIDs[v] | |
| n := r1.Intn(record.Len) | |
| names[i] = record.Members[n] | |
| groupIDs[v].Len-- | |
| groupIDs[v].Members = append(groupIDs[v].Members[:n], groupIDs[v].Members[n+1:]...) | |
| } | |
| assignments := make([]Assignments, 0, len(out)) | |
| for i, _ := range names { | |
| a, b := i, (i+1)%len(names) | |
| assignments = append(assignments, Assignments{From: names[a], To: names[b]}) | |
| } | |
| json.NewEncoder(os.Stdout).Encode(assignments) | |
| } | |
| func Interleave(h1, h2 []int) []int { | |
| out := make([]int, len(h1)+len(h2), len(h1)+len(h2)) | |
| ptr := 0 | |
| for i, _ := range h2 { | |
| if i == len(h1) { | |
| out[ptr] = h2[i] | |
| } else { | |
| out[ptr], out[ptr+1] = h2[i], h1[i] | |
| } | |
| ptr += 2 | |
| } | |
| return out | |
| } | |
| func valid(out []int) bool { | |
| return out[0] != out[len(out)-1] | |
| } | |
| func track(startTime time.Time) { | |
| endTime := time.Now() | |
| fmt.Println("took", endTime.Sub(startTime)) | |
| } |
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