C :

#include<stdio.h>
#include<string.h>

int main()
{
	int l,h,m,s,time=0,now=0,i;
	double v=0,d=0;
	char t[20];
	while(gets(t))
	{
		h=(t[0]-'0')*10+t[1]-'0';
		m=(t[3]-'0')*10+t[4]-'0';
		s=(t[6]-'0')*10+t[7]-'0';
		now=h*3600+m*60+s;
		l=strlen(t);
		if(l==8)
		{
			d+=(now-time)*v;
			printf("%s %.2lf km\n",t,d/1000);
			time=now;
		}
		else
		{
			d+=(now-time)*v;
			time=now;
			v=t[9]-'0';
			for(i=10;i<l;i++)
				v=v*10+t[i]-'0';
			v/=3.6;
		}
	}
	return 0;
}

Java :

 

import java.text.DecimalFormat;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner cin = new Scanner(System.in);
		int speed = 0;
		float distance = 0;
		int[] startTime = new int[3];
		boolean isStart = true;
		while (cin.hasNextLine()) {
			String hang = cin.nextLine();
			int lenght = hang.length();
			if (lenght <= 8) {
				String[] ts = hang.split(":");
				int[] endTime = new int[3];
				endTime[0] = Integer.parseInt(ts[0]);
				endTime[1] = Integer.parseInt(ts[1]);
				endTime[2] = Integer.parseInt(ts[2]);
				int h = endTime[0] - startTime[0];
				float m = endTime[1] - startTime[1];
				int s = endTime[2] - startTime[2];
				m += ((float) s) / 60f;
				float ddd = (h + m / 60f) * speed;
				DecimalFormat fnum = new DecimalFormat("##0.00"); 
				String re=fnum.format(ddd + distance); 
				System.out.println(hang+" "+re+" km");
			} else {
				String[] re_head = hang.split(" ");
				String[] ts = re_head[0].split(":");
				
				int[] endTime = new int[3];
				endTime[0] = Integer.parseInt(ts[0]);
				endTime[1] = Integer.parseInt(ts[1]);
				endTime[2] = Integer.parseInt(ts[2]);
				if (!isStart) {

					int h = endTime[0] - startTime[0];
					float m = endTime[1] - startTime[1];
					int s = endTime[2] - startTime[2];
					m += ((float) s) / 60f;
					float ddd = (h + m / 60f) * speed;
					distance += ddd;
				}
				speed = Integer.parseInt(re_head[1]);
				startTime[0] = endTime[0];
				startTime[1] = endTime[1];
				startTime[2] = endTime[2];
				isStart=false;
			}
			// System.out.println( lenght);
		}

	}

}