#P10962. [2015杭电多校]Group
[2015杭电多校]Group
Group
Problem Description
soda has a computer network consisting of n nodes numbered 1 through n. There are links in the network that connect pairs of nodes. A pair of nodes may have multiple links between them, but no node has a link to itself. A link can only transmit in a single direction. For two nodes and , if both and can transmit to each other (perhaps through some intermediate nodes), then and are in the same group. soda wants to increase the number of groups in the network by deleting a link. You need to tell him which link can be deleted.
Input
There are multiple test cases. The first line of input contains an integer , indicating the number of test cases. For each test case: The first contains two integer and , the number of nodes and the number links. Next lines contain two integers each, and , indicating there is a link between nodes and and the direction is from to .
Output
For each test case, output binary string of length . The -th character is '1' if soda can delete -th link to increase the number of groups, otherwise the -th character is '0'.
Sample Input
1
3 4
1 2
2 3
3 1
2 1
Sample Output
1110
Hint
If you need a larger stack size, please use #pragma comment(linker, "/STACK:102400000,102400000") and submit your solution using C++.
Author
zimpha@zju
Source
2015 Multi-University Training Contest 6