HDU 4708 Rotation Lock Puzzle
Rotation Lock PuzzleTime Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 659 Accepted Submission(s): 193
Problem Description
Alice was felling into a cave. She found a strange door with a number square matrix. These numbers can be rotated around the center clockwise or counterclockwise. A fairy came and told her how to solve this puzzle lock: “When the sum of main diagonal and anti-diagonal is maximum, the door is open.”.
Here, main diagonal is the diagonal runs from the top left corner to the bottom right corner, and anti-diagonal runs from the top right to the bottom left corner. The size of square matrix is always odd.
This sample is a square matrix with 5*5. The numbers with vertical shadow can be rotated around center ‘3’, the numbers with horizontal shadow is another queue. Alice found that if she rotated vertical shadow number with one step, the sum of two diagonals is maximum value of 72 (the center number is counted only once).
Input
Multi cases is included in the input file. The first line of each case is the size of matrix n, n is a odd number and 3<=n<=9.There are n lines followed, each line contain n integers. It is end of input when n is 0 .
Output
For each test case, output the maximum sum of two diagonals and minimum steps to reach this target in one line.
Sample Input
5
9 3 2 5 9
7 4 7 5 4
6 9 3 9 3
5 2 8 7 2
9 9 4 1 9
0
Sample Output
72 1
Source
2013 ACM/ICPC Asia Regional Online —— Warmup
import java.io.*; import java.math.BigInteger; import java.util.*; public class Main { BufferedReader bu; PrintWriter pw; int n; int[][] a; public static void main(String[] args) throws IOException { new Main().work(); } void work() throws IOException { bu = new BufferedReader(new InputStreamReader(System.in)); pw = new PrintWriter(new OutputStreamWriter(System.out),true); n = Integer.parseInt(bu.readLine()); while (n != 0) { a = new int[n][n]; for (int i = 0; i < n; i++) { String str[] = bu.readLine().split(" "); for (int j = 0; j < n; j++) { a[i][j] = Integer.parseInt(str[j]); } } BigInteger result = BigInteger.ZERO; int step = 0; for (int i = 0; i < n / 2; i++) {//控制圈数 BigInteger max = BigInteger.ZERO; int temp = 0; for (int j = i; j < n - 1 - i; j++) { BigInteger sum = BigInteger.ZERO; sum = sum.add(BigInteger.valueOf(a[i][j]));//第i圈的 第一行顺时针相加 sum = sum.add(BigInteger.valueOf(a[n - 1 - i][n - 1 - j]));//第i圈的最后一行逆时针相加 sum = sum.add(BigInteger.valueOf(a[j][n - 1 - i]));//第i圈的最后一列,顺时针相加 sum = sum.add(BigInteger.valueOf(a[n - 1 - j][i]));//第i圈的第一列,逆时针相加 int flag = Math.min(Math.abs(j - i),Math.abs(j - (n - 1 - i)));//每次转圈的最小步数 if (sum.compareTo(max) > 0) { max = sum; temp = flag; } else if (sum.compareTo(max) == 0 && temp > flag) { temp = flag; } } step += temp; result = result.add(max); } result = result.add(BigInteger.valueOf(a[n / 2][n / 2]));//最后再加上中心元素 pw.println(result + " " + step); n = Integer.parseInt(bu.readLine()); } } }
补充:软件开发 , C++ ,