Codeforces Round #411 (Div. 1), problem: (F) Fake bullions Solution In JAVA

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.StringTokenizer;

public class Div1_411F {

int numTV;
int A;
int B;

ArrayList<Integer>[] tAList;

boolean[][] tVAct;
int[] numM;

int cTime = 0;
int[] disc;
int[] low;

ArrayDeque<Integer> stack = new ArrayDeque<Integer>();

ArrayList<ArrayList<Integer>> sCCs = new ArrayList<ArrayList<Integer>>();

int numC;

boolean[][] compAct;

// represents the minimum and the maximum amounts of active members a tournament vertex can have
int[] min;
int[] max;

long MOD = 1_000_000_007L;

int[][] comb;

void dfs(int cV) {
disc[cV] = low[cV] = cTime++;
stack.push(cV);

for (int adj : tAList[cV]) {
if (disc[adj] == -1) {
dfs(adj);
}
if (low[adj] < low[cV]) {
low[cV] = low[adj];
}
}
if (disc[cV] == low[cV]) {
ArrayList<Integer> cSCC = new ArrayList<Integer>();
while (stack.peek() != cV) {
low[stack.peek()] = Integer.MAX_VALUE;
cSCC.add(stack.pop());
}
low[stack.pop()] = Integer.MAX_VALUE;
cSCC.add(cV);
sCCs.add(cSCC);
}
}

void findSCCs() {
disc = new int[numTV];
low = new int[numTV];
Arrays.fill(disc, -1);

for (int i = 0; i < numTV; i++) {
if (disc[i] == -1) {
dfs(i);
}
}

numC = sCCs.size();
}

int fGCD(int a, int b) {
while (b != 0) {
int t = b;
b = a % b;
a = t;
}
return a;
}

void condenseComps() {
compAct = new boolean[numC][];
for (int cComp = 0; cComp < numC; cComp++) {
ArrayList<Integer> cMems = sCCs.get(cComp);
int cGCD = numM[cMems.get(0)];
for (int j : cMems) {
cGCD = fGCD(cGCD, numM[j]);
}
boolean[] cCompSet = compAct[cComp] = new boolean[cGCD];
for (int cM : cMems) {
for (int sM = 0; sM < numM[cM]; sM++) {
if (tVAct[cM][sM]) {
cCompSet[sM % cGCD] = true;
}
}
}
}
}

void pushConnections() {
boolean[] cSet = compAct[numC – 1];

for (int cComp = numC – 2; cComp >= 0; cComp–) {
boolean[] pSet = cSet;
cSet = compAct[cComp];
int gcd = fGCD(pSet.length, cSet.length);

boolean[] resSet = new boolean[gcd];

for (int i = 0; i < pSet.length; i++) {
if (pSet[i]) {
resSet[i % gcd] = true;
}
}

for (int cRes = 0; cRes < gcd; cRes++) {
if(resSet[cRes]){
for (int cNum = cRes; cNum < cSet.length; cNum += gcd) {
cSet[cNum] = true;
}
}
}
}
}

void findMaxs() {
max = new int[numTV];

for (int cComp = 0; cComp < numC; cComp++) {
int aCnt = 0;
for (boolean b : compAct[cComp]) {
if (b) {
aCnt++;
}
}
for (int cM : sCCs.get(cComp)) {
max[cM] = numM[cM] / compAct[cComp].length * aCnt;
}
}
}

// uses Pascal’s identity
void preComb() {
comb = new int[numTV + 1][];
comb[0] = new int[] { 1 };
for (int i = 1; i <= numTV; i++) {
int[] pRow = comb[i – 1];
int[] cRow = comb[i] = new int[i + 1];
cRow[0] = 1;
for (int j = 1; j < i; j++) {
int val = pRow[j] + pRow[j – 1];
cRow[j] = val < 1_000_000_007 ? val : val – 1_000_000_007;
}
cRow[i] = 1;
}
}

long findAns() {
long ans = 0;

for (int sLws = 0; sLws < numTV; sLws++) {
int sGrt = 0;
int pGrt = 0;
for (int oth = 0; oth < numTV; oth++) {
if (oth == sLws) {
continue;
}
if (min[oth] > max[sLws]) {
if (++sGrt >= A) {
continue;
}
}

// secondary condition in case of equality to prevent overcounting
else if (max[oth] > max[sLws] || (max[oth] == max[sLws] && sLws < oth)) {
pGrt++;
}
}

// condition: B – 1 – sGrt <= numT
int s = B – 1 – sGrt;
for (int numT = s > 0 ? s : 0; numT < B && numT <= pGrt && numT + sGrt < A; numT++) {
ans = (ans + ((long) comb[pGrt][numT]) * comb[sGrt][B – 1 – numT]) % MOD;
}
}
return ans;
}

@SuppressWarnings(“unchecked”)
void execute() throws IOException {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

StringTokenizer inputData = new StringTokenizer(reader.readLine());
numTV = Integer.parseInt(inputData.nextToken());
A = Integer.parseInt(inputData.nextToken());
B = Integer.parseInt(inputData.nextToken());

tAList = new ArrayList[numTV];

for (int i = 0; i < numTV; i++) {
tAList[i] = new ArrayList<Integer>();
String nLine = reader.readLine();
for (int j = 0; j < numTV; j++) {
if (nLine.charAt(j) == ‘1’) {
tAList[i].add(j);
}
}
}

tVAct = new boolean[numTV][];
numM = new int[numTV];
min = new int[numTV];

for (int i = 0; i < numTV; i++) {
inputData = new StringTokenizer(reader.readLine());
int cNumM = numM[i] = Integer.parseInt(inputData.nextToken());
boolean[] cVAct = tVAct[i] = new boolean[cNumM];

String nLine = inputData.nextToken();
for (int j = 0; j < cNumM; j++) {
if (cVAct[j] = nLine.charAt(j) == ‘1’) {
min[i]++;
}
}
}
reader.close();

findSCCs();
condenseComps();
pushConnections();
findMaxs();
preComb();

long ans = findAns();
System.out.println(ans);
}

public static void main(String[] args) throws IOException {
new Div1_411F().execute();
}

}

Toshiba Starts Mass Production...

Toshiba Electronic Devices & Storage Corporation ("Toshiba") has officially...

I Tried Car Storage...

📢 As an Amazon Associate, I earn from qualifying...

Grok Creator SpaceXAI Sues...

In a dramatic legal clash between artificial intelligence developers...

Hello World from Antigravity...

Hello World! This blog post was automatically created and published...

Is Gaming Desk Accessories...

📢 As an Amazon Associate, I earn from qualifying...

Why Closet Organization Tools...

📢 As an Amazon Associate, I earn from qualifying...

Toshiba Starts Mass Production of Compact Microcontrollers with Arm® Cortex®‑M4 Core for Single-Motor Control Applications

Toshiba Electronic Devices & Storage Corporation ("Toshiba") has officially announced the commencement of mass production for its new compact microcontrollers powered by the high-performance...

I Tried Car Storage Solutions For 30 Days Here Is the Honest Truth

📢 As an Amazon Associate, I earn from qualifying purchases.There comes a point when you realise that tolerating a frustrating situation is costing you...

Grok Creator SpaceXAI Sues Minnesota AG to Stop Ban on Nudification

In a dramatic legal clash between artificial intelligence developers and state regulators, the legal team associated with Grok creator SpaceXAI has officially filed a...

Hello World from Antigravity IDE

Hello World! This blog post was automatically created and published directly from Antigravity IDE using the WordPress REST API!

Is Gaming Desk Accessories Worth Your Money Here Is Our Full Review

📢 As an Amazon Associate, I earn from qualifying purchases.Most products in this category disappoint within weeks. Cheap materials, vague instructions, and results that...

Why Closet Organization Tools Is Currently Breaking the Internet

📢 As an Amazon Associate, I earn from qualifying purchases.If you had told me six months ago that a single purchase would change how...

Everything Discussed During The Slitherine Next 2026 Event

Strategy game publisher and developer Slitherine recently hosted its dedicated digital showcase, Slitherine Next 2026, delivering an action-packed presentation tailored specifically for tactics enthusiasts...

Everything You Need to Know About Rechargeable Home Tech Right Now

📢 As an Amazon Associate, I earn from qualifying purchases.I stumbled across this while desperately trying to fix a recurring problem in my routine....

Russ Allbery: Review: Radiant Star

Science fiction enthusiasts and literary critics alike are turning their eyes toward the upcoming release of Radiant Star, the latest novel by award-winning author...