欧拉工程第11题

题目链接：https://projecteuler.net/problem=11

package projecteuler11to20;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.StringTokenizer;

class level11{
    void solve() throws NumberFormatException, IOException {
        String fileName="src\\projecteuler11to20\\p11.csv";
        int ncol=20;
        int nrow=20;
        int[][] numbers=new int[nrow][ncol];
        numbers=CSVFileReader(fileName,nrow,ncol);
        int max=caculate(numbers,nrow,ncol);
        System.out.println(max);
    }

    int caculate(int[][] a,int nrow,int ncol){
        int max=0;
        for(int i=0;i<nrow;i++){
            for(int j=0;j<ncol;j++){
                //横 +4
                int mul=a[i][j];
                for(int k=1;k<4 && (4+j)<ncol;k++){
                    mul*=a[i][j+k];
                }
                //System.out.print(mul+" "+max+",");
                if(mul>max) max=mul;

                //竖 +4
                mul=a[i][j];
                for(int k=1;k<4 &&(4+i)<nrow;k++){
                    mul*=a[i+k][j];
                }
                //System.out.print(mul+" "+max+",");
                if(mul>max) max=mul;
                //右下 +4
                mul=a[i][j];
                for(int k=1;k<4 &&(4+j)<ncol&&(4+i)<nrow;k++ ){
                    mul*=a[i+k][j+k];
                }
                //System.out.print(mul+" "+max+",");
                if(mul>max) max=mul;
                //右上 +4
                mul=a[i][j];
                for(int k=1;k<4&&(i+4)<ncol&&(j-4)>=0;k++){
                    mul*=a[i+k][j-k];
                }
            // System.out.print(mul+" "+max+",");
                if(mul>max) max=mul;
                //System.out.println();
            }
        }
        return max;

    }

    int[][] CSVFileReader(String fileName,int nrow,int ncol) throws NumberFormatException, IOException {

          File file = new File(fileName);
          int [][] numbers = new int [nrow][ncol];
          StringBuilder sb = new StringBuilder();
          String line = null;
          int row = 0;
          int col = 0;
          BufferedReader br = null;
            br = new BufferedReader(new FileReader(file));

            while( (line = br.readLine()) != null && row<nrow) {
                StringTokenizer st = new StringTokenizer(line,",");
                while (st.hasMoreTokens())
                {
                    //get next token and store it in the array
                    numbers[row][col] = Integer.parseInt(st.nextToken());//字符转换成数字
                    col++;
                }
                col = 0;
                row++;
              }
            br.close();
            return numbers;
    }
}
public class Problem11 {

    /** * @param args * @throws IOException * @throws NumberFormatException */
    public static void main(String[] args) throws NumberFormatException, IOException {
        // TODO Auto-generated method stub

        new level11().solve();
    }

}