2017.txt

北大ACM题目例程 详细的解答过程 程序实现 算法分析

import java.util.*;

public class Main {
	
	static public void main( String [] string ) throws Exception{
		Scanner cin = new Scanner( System.in );
		int n, x, y, sum, t;
		while( true ){
			sum = t = 0;
			n = cin.nextInt();
			if( n < 0 )
				break;
			while( n-- > 0 ) {
				x = cin.nextInt();
				y = cin.nextInt();
				sum += (y-t)*x;
				t = y;
			}
			System.out.println( sum + " miles" );
		}
	}
}