You have bought a car in order to drive from Waterloo to a big city. The odometer on their car is broken, so you cannot measure distance. But the speedometer and cruise control both work, so the car can maintain a constant speed which can be adjusted from time to time in response to speed limits, traffic jams, and border queues. You have a stopwatch and note the elapsed time every time the speed changes. From time to time you wonder, “how far have I come?”.
Standard input contains several lines of input: Each speed change is indicated by a line specifying the elapsed time since the beginning of the trip (hh:mm:ss), followed by the new speed in km/h. Each query is indicated by a line containing the elapsed time. At the outset of the trip the car is stationary. Elapsed times are given in non-decreasing order and there is at most one speed change at any given time.
For each query in standard input, you should print a line giving the time and the distance travelled, in the format below.
00:15:01 25.00 km
想法: 簡單的求距離，容易卡在精確度的問題以及I/O上，因為不定長度所以用字串存取再去分割 ，上網查了之後發現sscanf的回傳值代表正確的讀取數，而讀取失敗的則不會有影響(Ex:sscanf去分割4個變數，但在只有輸入三個變數的情形下並不會出錯，第4個變數值不會更動，而回傳值是3(假設型態皆正確))，於是利用sscanf來寫即可。