题目描述
Tracy gives Charlie a [Directed Acyclic Graph] with N vertices. Among these N vertices, K vertices are sources, and L vertices are sinks.
Find out the maximum number of edges this graph can have.
Note:
A source is a vertex with no incoming edge.
A sink is a vertex with no outgoing edge.
A vertex can be both, a source, and a sink.
------ Input Format ------
- First line will contain T, number of test cases. Then the test cases follow.
- Each test case contains of a single line of input, three space-separated integers N, K, and L - the number of vertices, the number of sources and the number of sinks respectively.
------ Output Format ------
- For each test case, output in a single line, the maximum number of edges this graph can have.
------ Constraints ------
$1 ≤ T ≤ 10^{5}$
$2 ≤ N ≤ 10^{9}$
$1 ≤ K < N$
$1 ≤ L < N$
----- Sample Input 1 ------
2
3 1 1
5 3 3
----- Sample Output 1 ------
3
4
----- explanation 1 ------
Test case $1$: Assume that the vertices are numbered $1,2,$ and $3$. Let $1$ be a source and $3$ be a sink. The edges of a possible DAG are $1\rightarrow 2, 2\rightarrow 3,$ and $1\rightarrow 3$.
The number of edges in this graph are $3$. It can be shown that this is the maximum number of edges possible under given constraints.
Test case $2$: Assume that the vertices are numbered $1,2,3,4,$ and $5$. Let $1,2,$ and $3$ be sources and $3, 4, $ and $5$ be sinks. The edges of a possible DAG are $1\rightarrow 4, 2\rightarrow 4, 1\rightarrow 5$ and $2\rightarrow 5$.
The number of edges in this graph are $4$. It can be shown that this is the maximum number of edges possible under given constraints.
输入格式
见题面
输出格式
见题面