Speed Limit |
Time Limit: 1000ms, Special Time Limit:2500ms, Memory Limit:32768KB |
Total submit users: 164, Accepted users: 162 |
Problem 10189 : No special judgement |
Problem description |
Bill and Ted are taking a road trip. But the odometer in their car is broken, so they don't know how many miles they have driven. Fortunately, Bill has a working stopwatch, so they can record their speed and the total time they have driven. Unfortunately, their record keeping strategy is a little odd, so they need help computing the total distance driven. You are to write a program to do this computation. For example, if their log shows Speed in miles perhour Total elapsed time in hours 20 2 30 6 10 7 this means they drove 2 hours at 20 miles per hour, then 6-2=4 hours at 30 miles per hour, then 7-6=1 hour at 10 miles per hour. The distance driven is then (2)(20) + (4)(30) + (1)(10) = 40 + 120 + 10 = 170 miles. Note that the total elapsed time is always since the beginning of the trip, not since the previous entry in their log. |
Input |
The input consists of one or more data sets. Each set starts with a line containing an integer n, 1 <= n <= 10, followed by n pairs of values, one pair per line. The first value in a pair, s, is the speed in miles per hour and the second value, t, is the total elapsed time. Both s and t are integers, 1 <= s <= 90 and 1 <= t <= 12. The values for t are always in strictly increasing order. A value of -1 for n signals the end of the input. |
Output |
For each input set, print the distance driven, followed by a space, followed by the word "miles" |
Sample Input |
3 20 2 30 6 10 7 2 60 1 30 5 4 15 1 25 2 30 3 10 5 -1 |
Sample Output |
170 miles 180 miles 90 miles |
Problem Source |
Mid-Central USA 2004 |
#include <stdio.h>
main()
{
int i,j,k,n;
int v=0,t=0,vinput,telapse,miles;
scanf("%d",&n);
while(n!=-1){
v=0;
t=0; //pre speed time
miles=0;
for(i=0;i<n;i++){
scanf("%d%d",&vinput,&telapse);
miles+=(telapse-t)*vinput;
t=telapse;
}
printf("%d miles ",miles);
scanf("%d",&n);
}
return 0;
}