给定具有N个顶点和M个边的无向图，任务是找到无向图中奇数度节点和偶数度节点的度之和之间的绝对差。
例子：
Input: N = 4, edges[][] = { { 1, 2 }, { 1, 3 }, { 1, 4 }, { 2, 3 }, { 2, 4 }, { 3, 4 } }
Output: 12
Explanation:
Below is the graph for the above information:
Node -> Degree
1 -> 3
2 -> 3
3 -> 3
4 -> 3
Sum of odd degree node = 3 + 3 + 3 + 3 = 12
Sum of even degree node = 0
Difference = 12
Input: N = 5, edges[][] = { { 1, 2 }, { 1, 3 }, { 2, 4 }, { 2, 5 } }
Output: 4
方法：
- 对于每个顶点，度可以通过给定图在相应顶点处的邻接表的长度来计算。
- 计算奇数度节点和偶数度节点的度数之和，然后打印出差异。
下面是上述方法的实现：
C++
// C++ implementation to print the
// Difference Between sum of degrees
// of odd degree nodes and even
// degree nodes.
#include
using namespace std;
// Function to print the difference
// Between sum of degrees of odd
// degree nodes and even degree nodes.
int OddEvenDegree(int N, int M,
int edges[][2])
{
// To store Adjacency List of
// a Graph
vector Adj[N + 1];
int EvenSum = 0;
int OddSum = 0;
// Make Adjacency List
for (int i = 0 ; i < M ; i++) {
int x = edges[i][0];
int y = edges[i][1];
Adj[x].push_back(y);
Adj[y].push_back(x);
}
// Traverse each vertex
for (int i = 1; i <= N; i++) {
// Find size of Adjacency List
int x = Adj[i].size();
// If length of Adj[i] is
// an odd number, add
// length in OddSum
if (x % 2 != 0)
{
OddSum += x;
}
else
{
// If length of Adj[i] is
// an even number, add
// length in EvenSum
EvenSum += x;
}
}
return abs(OddSum - EvenSum);
}
// Driver code
int main()
{
// Vertices and Edges
int N = 4, M = 6;
// Edges
int edges[M][2] = { { 1, 2 }, { 1, 3 }, { 1, 4 },
{ 2, 3 }, { 2, 4 }, { 3, 4 } };
// Function Call
cout<< OddEvenDegree(N, M, edges);
return 0;
} Java
// Java implementation to print the
// difference between sum of degrees
// of odd degree nodes and even
// degree nodes.
import java.util.*;
class GFG{
// Function to print the difference
// between sum of degrees of odd
// degree nodes and even degree nodes.
static int OddEvenDegree(int N, int M,
int edges[][])
{
// To store adjacency list
// of a graph
@SuppressWarnings("unchecked")
Vector []Adj = new Vector[N + 1];
for(int i = 0; i < N + 1; i++)
{
Adj[i] = new Vector();
}
int EvenSum = 0;
int OddSum = 0;
// Make adjacency list
for(int i = 0; i < M; i++)
{
int x = edges[i][0];
int y = edges[i][1];
Adj[x].add(y);
Adj[y].add(x);
}
// Traverse each vertex
for(int i = 1; i <= N; i++)
{
// Find size of adjacency list
int x = Adj[i].size();
// If length of Adj[i] is
// an odd number, add
// length in OddSum
if (x % 2 != 0)
{
OddSum += x;
}
else
{
// If length of Adj[i] is
// an even number, add
// length in EvenSum
EvenSum += x;
}
}
return Math.abs(OddSum - EvenSum);
}
// Driver code
public static void main(String[] args)
{
// Vertices and edges
int N = 4, M = 6;
// Edges
int edges[][] = { { 1, 2 }, { 1, 3 }, { 1, 4 },
{ 2, 3 }, { 2, 4 }, { 3, 4 } };
// Function call
System.out.print(OddEvenDegree(N, M, edges));
}
}
// This code is contributed by PrinciRaj1992 Python3
# Python3 implementation to print the
# Difference Between sum of degrees
# of odd degree nodes and even
# degree nodes.
# Function to print the difference
# Between sum of degrees of odd
# degree nodes and even degree nodes.
def OddEvenDegree(N, M, edges):
# To store Adjacency
# List of a Graph
Adj = [[] for i in range(N + 1)]
EvenSum = 0;
OddSum = 0;
# Make Adjacency List
for i in range(M):
x = edges[i][0];
y = edges[i][1];
Adj[x].append(y);
Adj[y].append(x);
# Traverse each vertex
for i in range(1, N + 1):
# Find size of
# Adjacency List
x = len(Adj[i])
# If length of Adj[i] is
# an odd number, add
# length in OddSum
if (x % 2 != 0):
OddSum += x;
else:
# If length of Adj[i] is
# an even number, add
# length in EvenSum
EvenSum += x;
return abs(OddSum - EvenSum);
# Driver code
if __name__ == "__main__":
# Vertices and Edges
N = 4
M = 6
# Edges
edges = [[1, 2], [1, 3],
[1, 4], [2, 3],
[2, 4], [3, 4]]
# Function Call
print(OddEvenDegree(N, M,
edges));
# This code is contributed by rutvik_56C#
// C# implementation to print the
// difference between sum of degrees
// of odd degree nodes and even
// degree nodes.
using System;
using System.Collections.Generic;
class GFG{
// Function to print the difference
// between sum of degrees of odd
// degree nodes and even degree nodes.
static int OddEvenDegree(int N, int M,
int [,]edges)
{
// To store adjacency list
// of a graph
List []Adj = new List[N + 1];
for(int i = 0; i < N + 1; i++)
{
Adj[i] = new List();
}
int EvenSum = 0;
int OddSum = 0;
// Make adjacency list
for(int i = 0; i < M; i++)
{
int x = edges[i, 0];
int y = edges[i, 1];
Adj[x].Add(y);
Adj[y].Add(x);
}
// Traverse each vertex
for(int i = 1; i <= N; i++)
{
// Find size of adjacency list
int x = Adj[i].Count;
// If length of Adj[i] is
// an odd number, add
// length in OddSum
if (x % 2 != 0)
{
OddSum += x;
}
else
{
// If length of Adj[i] is
// an even number, add
// length in EvenSum
EvenSum += x;
}
}
return Math.Abs(OddSum - EvenSum);
}
// Driver code
public static void Main(String[] args)
{
// Vertices and edges
int N = 4, M = 6;
// Edges
int [,]edges = {{1, 2}, {1, 3}, {1, 4},
{2, 3}, {2, 4}, {3, 4}};
// Function call
Console.Write(OddEvenDegree(N, M, edges));
}
}
// This code is contributed by Princi Singh 输出：
12