[Noip simulation questions] graph (Tarjan + DFS)

Seems like I am doing something too complicated?

First, the Tarjan point is reduced, and then the DFS line is Qaq.

(I did not say that I was mistakenly called by an SB for half an hour .... Don't think that after the scale-down, the DFS will be able to judge vis with no scrubs ..

BFS practice: subtract the reverse graph, and then enumerate (Greedy) from the largest to the smallest to mark it.

# Include <cstdio> # include <cstring> # include <cmath> # include <string> # include <iostream> # include <algorithm> # include <queue> # include <set> # include <vector> # include <map> using namespace STD; typedef long ll; # define PII pair <int, int> # define mkpii make_pair <int, int> # define PDI pair <double, int> # define mkpdi make_pair <double, int> # define PLI pair <LL, int> # define mkpli make_pair <LL, int> # define rep (I, n) for (INT I = 0; I <(n); ++ I) # define for1 (I, A, n) for (INT I = (a); I <= (n); ++ I) # define for2 (I, A, n) for (INT I = (); I <(n); ++ I) # define for3 (I, A, n) for (INT I = (a); I> = (n); -- I) # define for4 (I, A, n) for (INT I = (a); I> (n); -- I) # define CC (I, A) memset (I, a, sizeof (I) # define read (A) A = getint () # define print (a) printf ("% d", a) # define dbg (X) cout <(# X) <"=" <(x) <Endl # define error (x )(! (X )? Puts ("error"): 0) # define printarr2 (a, B, c) for1 (_, 1, B) {for1 (__, 1, C) cout <A [_] [_]; cout <Endl ;}# define printarr1 (a, B) for1 (_, 1, B) cout <A [_] <'\ T'; cout <endlinline const int getint () {int r = 0, k = 1; char c = getchar (); for (; C <'0' | C> '9'; C = getchar () if (C = '-') k =-1; (; c> = '0' & C <= '9'; C = getchar () r = r * 10 + C-'0'; return K * r ;} inline const int max (const Int & A, const Int & B ){ Return A> B? A: B;} inline const int min (const Int & A, const Int & B) {return a <B? A: B;} const int n = 1e5 + 10; int M, MX [N], ll [N], FF [N], vis [N], TOT, SCC, st [N], Fa [N], top; struct gr {int ihead [N], CNT, N; struct dat {int next, to;} e [N]; void add (int u, int v) {e [++ CNT]. next = ihead [u]; ihead [u] = CNT; E [CNT]. to = V;} void Tarjan () {for1 (I, 1, n) if (! FF [I]) Tarjan (I);} void Tarjan (INT X) {ll [x] = FF [x] = ++ tot; vis [x] = 1; st [++ top] = x; For (INT I = ihead [X]; I; I = E [I]. next) {int y = E [I]. to; If (! FF [y]) {Tarjan (y); LL [x] = min (LL [X], ll [y]);} else if (vis [y] & FF [y] <ll [x]) ll [x] = FF [y];} if (FF [x] = ll [x]) {++ SCC; int y; do {Y = sT [top --]; vis [y] = 0; fa [y] = SCC; MX [SCC] = max (MX [SCC], Y);} while (y! = X) ;}} void DFS () {CC (VIS, 0); for1 (I, 1, n) if (! Vis [I]) DFS (I);} void DFS (int x) {If (vis [x]) return; // I won't talk about it anymore... Vis [x] = 1; for (INT I = ihead [X]; I; I = E [I]. next) {DFS (E [I]. to); MX [x] = max (MX [X], MX [E [I]. to]) ;}}g, G; int main () {read (G. n); read (m); for1 (I, 1, m) {int u = getint (), V = getint (); G. add (u, v); w.g.tar Jan (); G. N = SCC; for1 (x, 1, G. n) for (INT I = G. ihead [X]; I; I = G. E [I]. next) if (Fa [x]! = Fa [G. E [I]. to]) g. add (Fa [X], Fa [G. E [I]. to]); G. DFS (); for1 (I, 1, G. n) printf ("% d", MX [Fa [I]); Return 0 ;}

　　

 

 

 

 

[Description]

Returns a directed graph of N points and m edges. For each vertex v, evaluate a (v) to indicate the largest vertex number that can be reached starting from vertex v.

 

[Input format]

1st rows, two integers n, m. In the next m row, there are two integers in each line. The UI, Vi, indicates the edge? UI, Vi ?. Point is numbered with 1, 2,..., n.

 

[Output format]

N integers A (1), a (2),..., a (n ).

 

[Example input]

4 3

1 2

2 4

4 3

[Sample output]

4 4 3 4

[Data Scope]

For 60% of the data, 1 ≤ n, k ≤ 10 ^ 3

For 100% of data, 1 ≤ n, m ≤ 10 ^ 5.

[Noip simulation questions] graph (Tarjan + DFS)