Submission #1646285

---

Source Code Expand

/+ dub.sdl:
    name "B"
    dependency "dcomp" version=">=0.6.0"
+/
 
import std.stdio, std.algorithm, std.range, std.conv;
// import dcomp.foundation, dcomp.scanner;

// import dcomp.graph.maxflow;
 
int main() {
    Scanner sc = new Scanner(stdin);
    int n;
    int[] u, d, l, r;
    sc.read(n, u, d, l, r);
 
    int[] ud = new int[n]; ud[] = u[] + d[];
    int[] lr = new int[n]; lr[] = l[] + r[];
 
    if (ud.count!(a => a>n) || lr.count!(a => a>n)) {
        writeln("NO");
        return 0;
    }
    struct E { int to, cap; int rev; }
 
    E[][] g = new E[][2*n + 2];
    void add(int from, int to, int cap) {
//        writeln("add ", from, " ", to, " ", cap);
        g[from] ~= E(to, cap, g[to].length.to!int);
        g[to] ~= E(from, 0, g[from].length.to!int-1);
    }
    int sv = 2*n, tv = sv+1;
    foreach (i; 0..n) {
        add(sv, i, ud[i]);
        add(n+i, tv, n-lr[i]);
    }
    foreach (y; 0..n) {
        foreach (x; 0..n) {
            add(x, y+n, 1);
        }
    }
 
    auto mf = maxFlow!(int, 0)(g, sv, tv);
    if (mf.flow != ud.sum()) {
        writeln("NO");
        return 0;
    }
//    if (50 <= n) return 0;
 
    int[][] dir = new int[][](n, n);
    foreach (x; 0..n) {
        int[] yv;
        foreach (e; g[x]) {
            if (e.to == sv) continue;
            if (e.cap == 1) continue;
            yv ~= e.to - n;
        }
        foreach (i, y; yv) {
            if (i < u[x]) {
                dir[y][x] = 0;
            } else {
                dir[y][x] = 1;
            }
        }
    }
    foreach (y; 0..n) {
        int[] xv;
        foreach (e; g[n+y]) {
            if (e.to == tv) continue;
            if (e.cap == 1) continue;
            xv ~= e.to;
        }
        foreach (i, x; xv) {
            if (i < l[y]) {
                dir[y][x] = 2;
            } else {
                dir[y][x] = 3;
            }
        }
    }
 
    bool[][] used = new bool[][](n, n);
    int usedc;
    int[][4] cnt = new int[][4];
    foreach (i; 0..4) cnt[i] = new int[n];
    cnt[1][] = n-1;
    cnt[3][] = n-1;
 
    int[2] mv(int x, int y) {
        int d = dir[y][x];
        if (d == 0 || d == 1) return [x, cnt[d][x]];
        else return [cnt[d][y], y];
    }
 
    bool update;
    void put(int x, int y) {
        assert(!used[y][x]);
        update = true;
        used[y][x] = true;
        int d = dir[y][x];
        int p = (d < 2 ? x : y) + 1;
        writeln("UDLR"[d], p);
        while (cnt[0][x] < n && used[cnt[0][x]][x]) cnt[0][x]++;
        while (cnt[1][x] >= 0 && used[cnt[1][x]][x]) cnt[1][x]--;
        while (cnt[2][y] < n && used[y][cnt[2][y]]) cnt[2][y]++;
        while (cnt[3][y] >= 0 && used[y][cnt[3][y]]) cnt[3][y]--;
    }
 
    int[][] mp = new int[][](n, n);
 
    while (true) {
        update = false;
//        writeln("ST");
//        foreach (v; dir) writeln(v);
 
        void dfs(int[2] st) {
            static int ph = 114514; ph++;
            if (st[0] < 0 || n <= st[0]) return;
            if (st[1] < 0 || n <= st[1]) return;
            while (mp[st[1]][st[0]] != ph) {
                mp[st[1]][st[0]] = ph;
                st = mv(st[0], st[1]);
            }
            if (mv(st[0], st[1]) == st) {
                put(st[0], st[1]);
                return;
            }
            int[2] ed = st;
            int bd = dir[st[1]][st[0]];
            while (true) {
                auto nx = mv(st[0], st[1]);
                swap(bd, dir[st[1]][st[0]]);
                st = nx;
                if (st == ed) break;
            }
            dir[ed[1]][ed[0]] = bd;
        }
 
        foreach (i; 0..n) {
            dfs([i, cnt[0][i]]);
        }
        foreach (i; 0..n) {
            dfs([i, cnt[1][i]]);
        }
        foreach (i; 0..n) {
            dfs([cnt[2][i], i]);
        }
        foreach (i; 0..n) {
            dfs([cnt[3][i], i]);
        }
 
        if (!update) break;
    }
 
    return 0;
}
/* IMPORT /Users/yosupo/Program/dcomp/source/dcomp/array.d */
// module dcomp.array;

 
T[N] fixed(T, size_t N)(T[N] a) {return a;}

 
 

 
struct FastAppender(A) {
    import std.algorithm : max;
    import std.range.primitives : ElementEncodingType;
    import core.stdc.string : memcpy;

    private alias T = ElementEncodingType!A;
    private T* _data;
    private size_t len, cap;
     
    @property size_t length() const {return len;}
    bool empty() const { return len == 0; }
     
    void reserve(size_t nlen) {
        import core.memory : GC;
        if (nlen <= cap) return;
        
        void* nx = GC.malloc(nlen * T.sizeof);

        cap = nlen;
        if (len) memcpy(nx, _data, len * T.sizeof);
        _data = cast(T*)(nx);
    }
     
    void opOpAssign(string op : "~")(T item) {
        if (len == cap) {
            reserve(max(4, cap*2));
        }
        _data[len++] = item;
    }
     
    void insertBack(T item) {
        this ~= item;
    }
     
    void removeBack() {
        len--;
    }
     
    void clear() {
        len = 0;
    }
    ref inout(T) back() inout { assert(len); return _data[len-1]; }
     
    T[] data() {
        return (_data) ? _data[0..len] : null;
    }
}

 
 
/* IMPORT /Users/yosupo/Program/dcomp/source/dcomp/graph/maxflow.d */
// module dcomp.graph.maxflow;

// import dcomp.container.deque, dcomp.array;

 
struct MaxFlowInfo(C) {
    C flow;  
    bool[] dual;  
}

 
MaxFlowInfo!(C) maxFlow(C, C EPS, T)(T g, int s, int t) {
    assert(s != t);
    import std.algorithm : map;
    import std.range : array;
    import std.conv : to;
    int n = g.length.to!int;
    int[] level = new int[n];
    int[] iter = new int[n];

    void bfs() {
        level[] = -1; level[s] = 0;
        auto que = Deque!int();
        que.insertBack(s);
        while (!que.empty) {
            int v = que.front; que.removeFront;
            foreach (e; g[v]) {
                if (e.cap <= EPS) continue;
                if (level[e.to] < 0) {
                    level[e.to] = level[v] + 1;
                    que.insertBack(e.to);
                }
            }
        }
    }

    C dfs(int v, C f) {
        import std.algorithm : min;
        if (v == t) return f;
        C res = 0;
        auto edgeList = g[v][iter[v]..$];
        foreach (ref e; edgeList) {
            if (e.cap <= EPS) continue;
            if (level[v] >= level[e.to]) continue;            
            C d = dfs(e.to, min(f, e.cap));
            e.cap -= d;
            g[e.to][e.rev].cap += d;
            res += d;
            f -= d;
            if (f == 0) break;
            iter[v]++;
        }
        return res;
    }

    C flow = 0;
    while (true) {
        bfs();
        if (level[t] < 0) break;
        iter[] = 0;
        while (true) {
            C f = dfs(s, C.max);
            if (!f) break;
            flow += f;
        }
    }

    auto mfInfo = MaxFlowInfo!C();
    mfInfo.flow = flow;
    mfInfo.dual = level.map!"a == -1".array;
    return mfInfo;
}


 
 


 

 
/* IMPORT /Users/yosupo/Program/dcomp/source/dcomp/scanner.d */
// module dcomp.scanner;

 
class Scanner {
    import std.stdio : File;
    import std.conv : to;
    import std.range : front, popFront, array, ElementType;
    import std.array : split;
    import std.traits : isSomeChar, isStaticArray, isArray; 
    import std.algorithm : map;
    File f;
    this(File f) {
        this.f = f;
    }
    char[512] lineBuf;
    char[] line;
    private bool succ() {
        import std.range.primitives : empty, front, popFront;
        import std.ascii : isWhite;
        while (true) {
            while (!line.empty && line.front.isWhite) {
                line.popFront;
            }
            if (!line.empty) break;
            if (f.eof) return false;
            line = lineBuf[];
            f.readln(line);
        }
        return true;
    }

    private bool readSingle(T)(ref T x) {
        import std.algorithm : findSplitBefore;
        import std.string : strip;
        import std.conv : parse;
        if (!succ()) return false;
        static if (isArray!T) {
            alias E = ElementType!T;
            static if (isSomeChar!E) {
                 
                 
                auto r = line.findSplitBefore(" ");
                x = r[0].strip.dup;
                line = r[1];
            } else {
                auto buf = line.split.map!(to!E).array;
                static if (isStaticArray!T) {
                     
                    assert(buf.length == T.length);
                }
                x = buf;
                line.length = 0;
            }
        } else {
            x = line.parse!T;
        }
        return true;
    }
    int read(T, Args...)(ref T x, auto ref Args args) {
        if (!readSingle(x)) return 0;
        static if (args.length == 0) {
            return 1;
        } else {
            return 1 + read(args);
        }
    }
}


 
 

 
/* IMPORT /Users/yosupo/Program/dcomp/source/dcomp/container/deque.d */
// module dcomp.container.deque;

struct DequePayload(T) {
    import core.exception : RangeError;
    import core.memory : GC;
    import std.range : ElementType, isInputRange;
    import std.traits : isImplicitlyConvertible;
    T *d;
    size_t st, length, cap;
    @property bool empty() const { return length == 0; }
    alias opDollar = length;
    ref inout(T) opIndex(size_t i) inout {
        version(assert) if (length <= i) throw new RangeError();
        return d[(st+i >= cap) ? (st+i-cap) : st+i];
    }
    private void expand() {
        import std.algorithm : max;
        assert(length == cap);
        auto nc = max(size_t(4), 2*cap);
        T* nd = cast(T*)GC.malloc(nc * T.sizeof);
        foreach (i; 0..length) {
            nd[i] = this[i];
        }
        d = nd; st = 0; cap = nc;
    }
    void clear() {
        st = length = 0;
    }
    void insertFront(T v) {
        if (length == cap) expand();
        if (st == 0) st += cap;
        st--; length++;
        this[0] = v; 
    }
    void insertBack(T v) {
        if (length == cap) expand();
        length++;
        this[length-1] = v; 
    }
    void removeFront() {
        assert(!empty, "Deque.removeFront: Deque is empty");        
        st++; length--;
        if (st == cap) st = 0;
    }
    void removeBack() {
        assert(!empty, "Deque.removeBack: Deque is empty");        
        length--;
    }
    
    ref inout(T) front() inout { return this[0]; }
    ref inout(T) back() inout { return this[$-1]; }
    Range opSlice() {return Range(&this, 0, length); }
    
    alias Range = RangeT!(DequePayload!T);
    alias ConstRange = RangeT!(const DequePayload!T);
    alias ImmutableRange = RangeT!(immutable DequePayload!T);

    static struct RangeT(A) {
        import std.traits : CopyTypeQualifiers;
        alias E = CopyTypeQualifiers!(A, T);
        A *p;
        size_t a, b;
        @property bool empty() const { return b <= a; }
        @property size_t length() const { return b-a; }
        @property RangeT save() { return RangeT(p, a, b); }
        @property RangeT!(const A) save() const {
            return typeof(return)(p, a, b);
        }
        alias opDollar = length;
        @property ref inout(E) front() inout { return (*p)[a]; }
        @property ref inout(E) back() inout { return (*p)[b-1]; }
        void popFront() {
            version(assert) if (empty) throw new RangeError();
            a++;
        }
        void popBack() {
            version(assert) if (empty) throw new RangeError();
            b--;
        }
        ref inout(E) opIndex(size_t i) inout { return (*p)[i]; }
        RangeT opSlice() { return this.save; }
        RangeT opSlice(size_t i, size_t j) {
            version(assert) if (i > j || a + j > b) throw new RangeError();
            return typeof(return)(p, a+i, a+j);
        }
        RangeT!(const A) opSlice() const { return this.save; }
        RangeT!(const A) opSlice(size_t i, size_t j) const {
            version(assert) if (i > j || a + j > b) throw new RangeError();
            return typeof(return)(p, a+i, a+j);
        }
    }
}


 
struct Deque(T, bool mayNull = true) {
    import core.exception : RangeError;
    import core.memory : GC;
    import std.range : ElementType, isInputRange;
    import std.traits : isImplicitlyConvertible;

    alias Payload = DequePayload!T;
    alias Range = Payload.Range;
    alias ConstRange = Payload.ConstRange;
    alias ImmutableRange = Payload.ImmutableRange;
    
    Payload* p;
    private void I() { if (mayNull && !p) p = new Payload(); }
    private void C() const {
        version(assert) if (mayNull && !p) throw new RangeError();
    }
    static if (!mayNull) {
        @disable this();
    }
     
    private this(Payload* p) {
        this.p = p;
    }
    this(U)(U[] values...) if (isImplicitlyConvertible!(U, T)) {
        p = new Payload();
        foreach (v; values) {
            insertBack(v);
        }
    }
     
    this(Range)(Range r)
    if (isInputRange!Range &&
    isImplicitlyConvertible!(ElementType!Range, T) &&
    !is(Range == T[])) {
        p = new Payload();
        foreach (v; r) {
            insertBack(v);
        }
    }
    static Deque make() { return Deque(new Payload()); }
    @property bool havePayload() const { return (!mayNull || p); }
     
    @property bool empty() const { return (!havePayload || p.empty); }
     
    @property size_t length() const { return (havePayload ? p.length : 0); }
     
    alias opDollar = length;
    ref inout(T) opIndex(size_t i) inout {C; return (*p)[i]; }
     
    ref inout(T) front() inout {C; return (*p)[0]; }
     
    ref inout(T) back() inout {C; return (*p)[$-1]; }
    void clear() { if (p) p.clear(); }
     
    void insertFront(T v) {I; p.insertFront(v); }
     
    void insertBack(T v) {I; p.insertBack(v); }
     
    alias stableInsertBack = insertBack;
     
    void removeFront() {C; p.removeFront(); }
     
    void removeBack() {C; p.removeBack(); }
     
    Range opSlice() {I; return Range(p, 0, length); }
}

 
 

 

 

 

 

 

 
/* IMPORT /Users/yosupo/Program/dcomp/source/dcomp/foundation.d */
// module dcomp.foundation;
 
static if (__VERSION__ <= 2070) {
    /*
    Copied by https://github.com/dlang/phobos/blob/master/std/algorithm/iteration.d
    Copyright: Andrei Alexandrescu 2008-.
    License: $(HTTP boost.org/LICENSE_1_0.txt, Boost License 1.0).
    */
    template fold(fun...) if (fun.length >= 1) {
        auto fold(R, S...)(R r, S seed) {
            import std.algorithm : reduce;
            static if (S.length < 2) {
                return reduce!fun(seed, r);
            } else {
                import std.typecons : tuple;
                return reduce!fun(tuple(seed), r);
            }
        }
    }
     
}
version (X86) static if (__VERSION__ < 2071) {
    import core.bitop : bsf, bsr, popcnt;
    int bsf(ulong v) {
        foreach (i; 0..64) {
            if (v & (1UL << i)) return i;
        }
        return -1;
    }
    int bsr(ulong v) {
        foreach_reverse (i; 0..64) {
            if (v & (1UL << i)) return i;
        }
        return -1;   
    }
    int popcnt(ulong v) {
        int c = 0;
        foreach (i; 0..64) {
            if (v & (1UL << i)) c++;
        }
        return c;
    }
}

/*
This source code generated by dcomp and include dcomp's source code.
dcomp's Copyright: Copyright (c) 2016- Kohei Morita. (https://github.com/yosupo06/dcomp)
dcomp's License: MIT License(https://github.com/yosupo06/dcomp/blob/master/LICENSE.txt)
*/

Submission Info

Judge Result