java.util.Scanner#nextInt ( )源码实例Demo

public static void main(String[] args) {
	Scanner input = new Scanner(System.in);
	int numberOfTestCases = input.nextInt();
	while (numberOfTestCases != 0) {
		BigInteger first = input.nextBigInteger();
		BigInteger second = input.nextBigInteger();
		StringBuilder firstString = new StringBuilder(first + "");
		StringBuilder secondString = new StringBuilder(second + "");
		BigInteger firstReversed = new BigInteger(firstString.reverse()
				.toString());
		BigInteger secondReversed = new BigInteger(secondString.reverse()
				.toString());
		BigInteger result = firstReversed.add(secondReversed);
		String resultReversed = new StringBuilder(result + "").reverse()
				.toString();
		System.out.println(resultReversed.replaceFirst("^0*", ""));
		numberOfTestCases--;
	}
}
 

public static void main(String[] args) {
	Scanner sc = new Scanner(System.in);
	int N = sc.nextInt();
	int K = sc.nextInt();
	int win = 0;
	int a[] = new int[N];
	int sum = 0;
	for (int i = 0; i < N; i++) {
		int temp = sc.nextInt();
		if (sc.nextInt() == 1) {
			win++;
			a[i] = temp;
		} else {
			a[i] = Integer.MAX_VALUE;
		}
		sum += temp;
	}
	sort(a, 0, a.length - 1);
	int s2 = 0;
	for (int i = 0; i < win - K; i++) {
		s2 += a[i];
	}

	System.out.println(sum - 2 * s2);
	sc.close();
}
 

public static void main(String[] args) {
	Scanner input = new Scanner(System.in);

	// Generate three random integers 
	int digit1 = (int)(Math.random() * 10);
	int digit2 = (int)(Math.random() * 10);
	int digit3 = (int)(Math.random() * 10);

	// Prompt user to enter the sum of three integers
	System.out.print(
		"What is " + digit1 + " + " + digit2 + " + " + digit3 + "? ");
	int answer = input.nextInt();
	
	System.out.println(
		digit1 + " + " + digit2 + " + " + digit3 + " = " + answer + " is " +
		(digit1 + digit2 + digit3 == answer));
}
 

public static void main(String[] args) {
	Scanner input = new Scanner(System.in);
	Integer[] numbers = new Integer[10];

	// Prompt the user to enter 10 integers
	System.out.print("Enter 10 integers: ");
	for (int i = 0; i < numbers.length; i++)
		numbers[i] = input.nextInt();
	
	// Create Integer BST
	BST<Integer> intTree = new BST<>(numbers);

	// Traverse tree preorder
	System.out.print("Tree preorder: ");
	intTree.preorder();
	System.out.println();
}
 

public static void main(String[] args) {
	Scanner scan = new Scanner(System.in);
	int n = scan.nextInt();

	Player[] player = new Player[n];
	Checker checker = new Checker();

	for (int i = 0; i < n; i++) {
		player[i] = new Player(scan.next(), scan.nextInt());
	}
	scan.close();

	Arrays.sort(player, checker);
	for (int i = 0; i < player.length; i++) {
		System.out.printf("%s %s\n", player[i].name, player[i].score);
	}
}
 

public static void main(String[] args) {
	Scanner in = new Scanner(System.in);
	int n = in.nextInt();
	in.close();
	int r = n, counter = 0, maxOne = 0;
	String s = "";
	while (n > 0) {

		r = n % 2;
		if (r == 1) {
			counter++;
			if (counter > maxOne) {
				maxOne = counter;
			}
		} else {
			counter = 0;
		}
		s = r + s;
		n = n / 2;

	}
	System.out.println(maxOne);

}
 

/** Main method */
public static void main(String[] args) {
	Scanner input = new Scanner(System.in); // Create a Scanner

	// Prompt the user to enter the number of the balls
	System.out.print("Enter the number of balls to drop: ");
	int drops = input.nextInt();

	// Prompt the user to enter the number of slots
	System.out.print("Enter the number of slots in the bean machine: ");
	int nails = input.nextInt() - 1;

	String[] paths = new String[nails * drops]; // Path of each ball
	int[] balls = new int[nails]; // The slot of each ball 

	int numberOfRs = 0; // The number of Rs in a path
	for (int i = 0; i < paths.length; i++) {
		paths[i] = getRandomPath();

		// If if ball path is right increament numberOfRs
		if (paths[i] == "R") {
			numberOfRs++; 
		}

		// Count the number of balls in each slot
		if ((i + 1) % nails == 0) {
			balls[numberOfRs]++; 
			numberOfRs = 0;
		}
	}	

	// Display the path of the balls
	print(paths, nails);
	
	// Display the the final buildup of the balls in the slots in a histogram 
	print(balls);

}
 

static Object[] load(Scanner scanner) {
    int n = scanner.nextInt();
    int m = scanner.nextInt();
    int[][] shots = new int[n][2];
    for (int i = 0; i < n; ++i) {
        shots[i][0] = scanner.nextInt();
        shots[i][1] = scanner.nextInt();
    }
    int[][] players = new int[m][2];
    for (int i = 0; i < m; ++i) {
        players[i][0] = scanner.nextInt();
        players[i][1] = scanner.nextInt();
    }
    return new Object[]{shots, players};
}
 

public EdgeWeightedGraph(Scanner sc) {
	this(sc.nextInt());
	int E = sc.nextInt();
	for (int i = 0; i < E; i++) {
		int v = sc.nextInt();
		int w = sc.nextInt();
		double weight = sc.nextDouble();
		Edge e = new Edge(v, w, weight);
		addEdge(e);
	}
}
 

public static void main(String[] args) {
    int a;
    //напишите тут ваш код
    Scanner sc = new Scanner(System.in);
    a = sc.nextInt();
    System.out.println (a*a);
}
 

private static Integer acceptChoice(Scanner reader){
	System.out.println("************Advanced Calculator************");
	System.out.println("1. Prime Number check");
	System.out.println("2. Even Number check");
	System.out.println("3. Sum of N Primes");
	System.out.println("4. Sum of N Evens");
	System.out.println("5. Sum of N Odds");
	System.out.println("6. Simple Interest");
	System.out.println("7. Compound Interest");
	System.out.println("8. Exit");
	System.out.println("Enter the number to choose operation");
	return reader.nextInt();
}
 

public static void main(String[] args) {
  final int NUMBER_OF_DAYS = 10;
  final int NUMBER_OF_HOURS = 24;
  double[][][] data 
    = new double[NUMBER_OF_DAYS][NUMBER_OF_HOURS][2];

  Scanner input = new Scanner(System.in);
  // Read input using input redirection from a file
  for (int k = 0; k < NUMBER_OF_DAYS * NUMBER_OF_HOURS; k++) {
    int day = input.nextInt(); 
    int hour = input.nextInt();
    double temperature = input.nextDouble();
    double humidity = input.nextDouble();
    data[day - 1][hour - 1][0] = temperature;
    data[day - 1][hour - 1][1] = humidity;
  }

  // Find the average daily temperature and humidity
  for (int i = 0; i < NUMBER_OF_DAYS; i++) {
    double dailyTemperatureTotal = 0, dailyHumidityTotal = 0;
    for (int j = 0; j < NUMBER_OF_HOURS; j++) {
      dailyTemperatureTotal += data[i][j][0];
      dailyHumidityTotal += data[i][j][1];
    }
 
    // Display result
    System.out.println("Day  " + i + "'s average temperature is " 
      + dailyTemperatureTotal / NUMBER_OF_HOURS);
    System.out.println("Day  " + i + "'s average humidity is " 
      + dailyHumidityTotal / NUMBER_OF_HOURS);
  }       
}
 

public Country(Scanner in) {
    if (in.hasNextLine()) {
        this.name = in.next();
        this.population = in.nextInt();
        this.area = in.nextInt();
        this.landlocked = in.nextBoolean();
    }
}
 

public static void main(String[] args) {
	Scanner sc = new Scanner(System.in);
	int t = sc.nextInt();
	int a[] = new int[t];
	for (int i = 0; i < t; i++) {
		a[i] = sc.nextInt();
	}
	Arrays.sort(a);
	int minDiff = Integer.MAX_VALUE;
	int min1 = 0;
	int min2 = 0, minIndex = -1;

	String result = "";
	for (int i = 1; i < t; i++) {
		int diff = Math.abs(a[i] - a[i - 1]);
		if (diff < minDiff) {
			minDiff = diff;
			min1 = a[i - 1];
			min2 = a[i];
			minIndex = i;
			result = min1 + " " + min2;
		}
	}
	for (int i = minIndex + 1; i < t; i++) {
		if (minDiff == Math.abs(a[i] - a[i - 1])) {
			result = result + " " + a[i - 1] + " " + a[i];
		}
	}
	System.out.println(result);
	sc.close();
}
 

public static void main(String[] args) {
	// TODO Auto-generated method stub
	int m, n, c, d;
	Scanner in = new Scanner(System.in);
	
	System.out.println("Enter the number of the rows of the matrix: ");
	m = in.nextInt();
	System.out.println("Enter the number of the columns of the matrix: ");
	n = in.nextInt();
	MatrixOperations instance = new MatrixOperations();

	System.out.println("Enter the elements of the first matrix:");
	BigDecimal[][] first = instance.createMatrix(m,n,in);
	
	System.out.println("Enter the elements of the second matrix:");
	BigDecimal[][] second = instance.createMatrix(m,n,in);
	
	System.out.println("Enter the value to be multiplied with:");
	int x = in.nextInt();
	BigDecimal value = new BigDecimal(x); 
	//instance.add(first, second);
	//instance.subtract(first, second);
	//instance.multiplyWithScalar(first, value);
	//instance.multiply(first, second);
	//System.out.println(instance.isEqual(first, second));
	//System.out.println(instance.isZero(first));
	//System.out.println(instance.isIdentityMatrix(first));
	//System.out.println(instance.determinant(first));
	System.out.println(instance.fillDegree(first));
}
 

public int getInt(String key, int def) {
  String str = readKeyFile(key);
  Scanner scan = new Scanner(str);
  if (scan.hasNextInt()) {
    return scan.nextInt();
  } else {
    return def;
  }
}
 

/** Main method */
public static void main(String[] args) {
	// Create a Scanner
	Scanner input = new Scanner(System.in);
	boolean continueInput = true;

	do {
		// Enter annual interest rate
		System.out.print(
			"Enter annual interest rate, for example, 8.25: ");
		double annualInterestRate = input.nextDouble();

		// Enter number of years
		System.out.print("Enter number of years as an integer: ");
		int numberOfYeras = input.nextInt();

		// Enter loan amount
		System.out.print("Enter loan amount, for example, 120000.95: ");
		double loanAmount = input.nextDouble();


		try {
			// Create a Loan object
			Loan loan =
				new Loan(annualInterestRate, numberOfYeras, loanAmount);	
			continueInput = false;

			// Display loan date, monthly payment, and total payment
			System.out.printf("The loan was created on %s\n" + 
				"The monthly payment is %.2f\nTne total payment is %.2f\n",
				loan.getLoanDate().toString(), loan.getMonthlyPayment(),
				loan.getTotalPayment());
		}
		catch (IllegalArgumentException ex) {
			System.out.println(ex.getMessage());
		}
	} while (continueInput);
}
 

public static void main(String[] args) throws Exception {
    //напишите тут ваш код
    Scanner sc = new Scanner(System.in);

    String str = sc.nextLine();
    int age = sc.nextInt();

    if (age>20)
        System.out.println("И 18-ти достаточно");
}
 

public static void main(String arg[]){
	Scanner number = new Scanner(System.in);
	int ok=1,i,k=1,num;
	long n1=0,n2=0,n3=0,n4=0;
	long sumprim=0,sumelse=1;
	long totalnum=0;
	double raport=0;
	System.out.println("Please insert the value of range");
	num = number.nextInt();
	//while(ok==1){
	for(i=2,k=1;i<=num;i=i+2,k=k+2){
		n1=(long)Math.pow(i+1,2);
		n2=n1-k-1;
		n3=n1-2*k-2;
		n4=n1-3*k-3;
	//}
		System.out.println(n1+" "+n2+" "+n3+" "+n4+" ");
	if(prim(n1))
		sumprim=sumprim+1;
	else
		sumelse=sumelse+1;
	
	if(prim(n2))
		sumprim=sumprim+1;
	else
		sumelse=sumelse+1;
	
	if(prim(n3))
		sumprim=sumprim+1;
	else
		sumelse=sumelse+1;
	
	if(prim(n4))
		sumprim=sumprim+1;
	else
		sumelse=sumelse+1;
	totalnum=sumelse+sumprim;
	raport=((double)sumprim)/((double)totalnum);
	if(raport<0.10)
		ok=0;
	//System.out.println("The lenght must be" +num);
	//num++;
	
	}
	System.out.println("Sumprim " +sumprim);
	System.out.println("Sumelse " +totalnum);
	System.out.println("is" +raport);
	System.out.println("The lenght must be" +num);
}
 

/**
 * 
 * @param args
 * the param args are not used
 */
public static void main(final String[] args) {
	
	Scanner sc = new Scanner(System.in);
	
	long suma3, suma5, suma15; // An overflow occurs for an integer variable 
	long total, n, number;   // for a number > 80.265, so we take long numbers
	// for long variables, we can read a number > 1.000.000.000
	
	System.out.println("Enter the number: ");
	number = sc.nextInt();
	
if (number % 3 == 0) {
		n = number / 3 - 1;	
		}
	else {
		n = number / 3;
	}
	
	suma3 = 3 * n * (n + 1) / 2;
	
	if (number % 5 == 0) {
		n = number / 5 - 1;
	}
	
	else {
		n = number / 5;
	}
	
	suma5 = 5 * n * (n + 1) / 2;
	
	if (number % 15 == 0) {
		n = number / 15 - 1;
	}
	else {
		n = number / 15;
	}
	
	suma15 = 15 * n * (n + 1) / 2;
	
	total = suma3 + suma5 - suma15;
	System.out.println("The sum is:" + total);
	System.out.println("An overflow occur for an integer variable for : " + Integer.MAX_VALUE);
	System.out.println("An overflow occur for a long variable for : " + Long.MAX_VALUE);
	sc.close();
	}