DouKaku?

module doukaku;
private import std.stdio;
private import std.random;

void remove(int[] ary, int pos) {
    if (ary.length != pos+1)
        for (int i=pos+1; i < ary.length; i++)
            ary[i-1] = ary[i];
    ary.length = ary.length - 1;
}

int[] lot(int n, int m) {
    int i;
    int[] lot, ret;
    for (i=1; i<=n; i++) lot ~= i;

    for (i=1; i<=m; i++) {
        int pos = rand() % lot.length;
        int x = lot[pos];
        remove(lot, pos);
        lot.length = lot.length - 1;
        ret ~= x;
    }
    return ret;
}

void print_lot(int n, int m) {
    foreach(x; lot(n, m)) writefln(x);
}

void main() {
    print_lot(9999, 4);
}