Canadian Computing Competition: 2000 Stage 1, Junior #4, Senior #2
A series of streams run down the side of a mountain. The mountainside is very rocky so the streams split and rejoin many times. At the foot of the mountain, several streams emerge as rivers. Your job is to compute how much water flows in each river.
At any given elevation there are streams, labelled to from left-to-right. As we proceed down the mountainside, one of the streams may split into a left fork and a right fork, increasing the total number of streams by , or two streams may rejoin, reducing the total number of streams by . After a split or a rejoining occurs, the streams are renumbered consecutively from left-to-right. There is always at least one stream and there are never more than streams.
The first line of input contains , the initial number of streams at some high altitude. The next lines give the flow in each of the streams from left-to-right. Proceeding down the mountainside, several split or rejoin locations are encountered. For each split location, there will be three lines of input.
- a line containing
99(to indicate a split)
- a line containing an integer, the number of the stream that is split
- a line containing an integer between and , the percentage of flow from the split stream that flows to the left fork. (The rest flows to the right fork)
For each join location, there will be two lines of input:
- a line containing
88(to indicate a join)
- a line containing an integer, the number of the stream that is rejoined with the stream to its right
The flow from both joined streams is combined. After the last split or join location will be:
- a single line containing
77(to indicate end of input)
Your job is to determine how many streams emerge at the foot of the mountain and what the flow is in each. Your output is a sequence of real numbers, rounded to the nearest integer, giving the flow in rivers through .
3 10 20 30 99 1 50 88 3 88 2 77
Can anyone explain to me why the output stream is 5? after 1 split and 2 rejoin? thz
rivers at first:
10 20 30
after 1st split:
5 5 20 30
(1st river is split 50:50)
after 1st join:
5 5 50
(3rd river combines with the river to the right)
after 2nd join:
so the final outcome is:
When splitting or merging, left and right is based on your view of the mountain (i.e., the direction is not relative to the split).