A11644. Dependency management
编程题
普及/提高-
知识点
题目描述
The first line contains an only integer $n$ ( $1<=n<=1000$ ) — the number of projects in Vaja.
The following lines contain the project descriptions. Each project is described by a line consisting of its name and version separated by space. The next line gives the number of direct dependencies (from $0$ to $n-1$ ) and the dependencies themselves (one in a line) in arbitrary order. Each dependency is specified by its name and version. The projects are also given in arbitrary order, but the first of them is always Polycarp's. Project descriptions are separated by one empty line. Refer to samples for better understanding.
It's guaranteed that there are no cyclic dependencies.
The following lines contain the project descriptions. Each project is described by a line consisting of its name and version separated by space. The next line gives the number of direct dependencies (from $0$ to $n-1$ ) and the dependencies themselves (one in a line) in arbitrary order. Each dependency is specified by its name and version. The projects are also given in arbitrary order, but the first of them is always Polycarp's. Project descriptions are separated by one empty line. Refer to samples for better understanding.
It's guaranteed that there are no cyclic dependencies.
输入格式
Output all Polycarp's project's dependencies in lexicographical order.
输出格式
The first sample is given in the pic below. Arrow from $A$ to $B$ means that $B$ directly depends on $A$ . Projects that Polycarp's project «a» (version $3$ ) depends on are painted black.
The second sample is again given in the pic below. Arrow from $A$ to $B$ means that $B$ directly depends on $A$ . Projects that Polycarp's project «codehorses» (version $5$ ) depends on are paint it black. Note that «extra 1» is chosen instead of «extra 3» since «mashadb 1» and all of its dependencies are ignored due to «mashadb 2».
The second sample is again given in the pic below. Arrow from $A$ to $B$ means that $B$ directly depends on $A$ . Projects that Polycarp's project «codehorses» (version $5$ ) depends on are paint it black. Note that «extra 1» is chosen instead of «extra 3» since «mashadb 1» and all of its dependencies are ignored due to «mashadb 2».
输入输出样例
输入 #1
4 a 3 2 b 1 c 1 b 2 0 b 1 1 b 2 c 1 1 b 2
输出 #1
2 b 1 c 1
输入 #2
9 codehorses 5 3 webfrmk 6 mashadb 1 mashadb 2 commons 2 0 mashadb 3 0 webfrmk 6 2 mashadb 3 commons 2 extra 4 1 extra 3 extra 3 0 extra 1 0 mashadb 1 1 extra 3 mashadb 2 1 extra 1
输出 #2
4 commons 2 extra 1 mashadb 2 webfrmk 6
输入 #3
3 abc 1 2 abc 3 cba 2 abc 3 0 cba 2 0
输出 #3
1 cba 2
说明/提示
The first sample is given in the pic below. Arrow from $A$ to $B$ means that $B$ directly depends on $A$ . Projects that Polycarp's project «a» (version $3$ ) depends on are painted black.
The second sample is again given in the pic below. Arrow from $A$ to $B$ means that $B$ directly depends on $A$ . Projects that Polycarp's project «codehorses» (version $5$ ) depends on are paint it black. Note that «extra 1» is chosen instead of «extra 3» since «mashadb 1» and all of its dependencies are ignored due to «mashadb 2».
The second sample is again given in the pic below. Arrow from $A$ to $B$ means that $B$ directly depends on $A$ . Projects that Polycarp's project «codehorses» (version $5$ ) depends on are paint it black. Note that «extra 1» is chosen instead of «extra 3» since «mashadb 1» and all of its dependencies are ignored due to «mashadb 2».
