在矩阵中查找总和最大的行
给定一个 N*N 矩阵。任务是找到总和最大的行的索引。那是元素总和最大的行。
例子：
Input : mat[][] = {
{ 1, 2, 3, 4, 5 },
{ 5, 3, 1, 4, 2 },
{ 5, 6, 7, 8, 9 },
{ 0, 6, 3, 4, 12 },
{ 9, 7, 12, 4, 3 },
};
Output : Row 3 has max sum 35
Input : mat[][] = {
{ 1, 2, 3 },
{ 4, 2, 1 },
{ 5, 6, 7 },
};
Output : Row 3 has max sum 18这个想法是逐行遍历矩阵并找到每行中元素的总和，并检查每一行当前的总和是否大于直到当前行获得的最大总和，并相应地更新 maximum_sum。
下面是上述方法的实现：
C++
// C++ program to find row with
// max sum in a matrix
#include
using namespace std;
#define N 5 // No of rows and column
// Function to find the row with max sum
pair colMaxSum(int mat[N][N])
{
// Variable to store index of row
// with maximum
int idx = -1;
// Variable to store max sum
int maxSum = INT_MIN;
// Traverse matrix row wise
for (int i = 0; i < N; i++) {
int sum = 0;
// calculate sum of row
for (int j = 0; j < N; j++) {
sum += mat[i][j];
}
// Update maxSum if it is less than
// current sum
if (sum > maxSum) {
maxSum = sum;
// store index
idx = i;
}
}
pair res;
res = make_pair(idx, maxSum);
// return result
return res;
}
// Driver code
int main()
{
int mat[N][N] = {
{ 1, 2, 3, 4, 5 },
{ 5, 3, 1, 4, 2 },
{ 5, 6, 7, 8, 9 },
{ 0, 6, 3, 4, 12 },
{ 9, 7, 12, 4, 3 },
};
pair ans = colMaxSum(mat);
cout << "Row " << ans.first + 1 << " has max sum "
<< ans.second;
return 0;
} Java
// Java program to find row with
// max sum in a matrix
import java.util.ArrayList;
class MaxSum
{
public static int N;
static ArrayList colMaxSum(int mat[][])
{
// Variable to store index of row
// with maximum
int idx = -1;
// Variable to store maximum sum
int maxSum = Integer.MIN_VALUE;
// Traverse the matrix row wise
for (int i = 0; i < N; i++)
{
int sum = 0;
for (int j = 0; j < N; j++)
{
sum += mat[i][j];
}
// Update maxSum if it is less than
// current row sum
if (maxSum < sum)
{
maxSum = sum;
// store index
idx = i;
}
}
// Arraylist to store values of index
// of maximum sum and the maximum sum together
ArrayList res = new ArrayList<>();
res.add(idx);
res.add(maxSum);
return res;
}
// Driver code
public static void main(String[] args)
{
N = 5;
int[][] mat = {
{ 1, 2, 3, 4, 5 },
{ 5, 3, 1, 4, 2 },
{ 5, 6, 7, 8, 9 },
{ 0, 6, 3, 4, 12 },
{ 9, 7, 12, 4, 3 },
};
ArrayList ans = colMaxSum(mat);
System.out.println("Row "+ (ans.get(0)+1)+ " has max sum "
+ ans.get(1));
}
}
// This code is contributed by Vivekkumar Singh Python3
# Python3 program to find row with
# max sum in a matrix
import sys
N = 5 # No of rows and column
# Function to find the row with max sum
def colMaxSum(mat):
# Variable to store index of row
# with maximum
idx = -1
# Variable to store max sum
maxSum = -sys.maxsize
# Traverse matrix row wise
for i in range(0, N):
sum = 0
# calculate sum of row
for j in range(0, N):
sum += mat[i][j]
# Update maxSum if it is less than
# current sum
if (sum > maxSum):
maxSum = sum
# store index
idx = i
res = [idx, maxSum]
# return result
return res
# Driver code
mat = [[ 1, 2, 3, 4, 5],
[ 5, 3, 1, 4, 2],
[ 5, 6, 7, 8, 9],
[ 0, 6, 3, 4, 12],
[ 9, 7, 12, 4, 3]]
ans = colMaxSum(mat)
print("Row", ans[0] + 1, "has max sum", ans[1])
# This code is contributed by Sanjit_PrasadC#
// C# program to find row with
// max sum in a matrix
using System;
using System.Collections.Generic;
public class MaxSum
{
public static int N;
static List colMaxSum(int [,]mat)
{
// Variable to store index of row
// with maximum
int idx = -1;
// Variable to store maximum sum
int maxSum = int.MinValue;
// Traverse the matrix row wise
for (int i = 0; i < N; i++)
{
int sum = 0;
for (int j = 0; j < N; j++)
{
sum += mat[i, j];
}
// Update maxSum if it is less than
// current row sum
if (maxSum < sum)
{
maxSum = sum;
// store index
idx = i;
}
}
// Arraylist to store values of index
// of maximum sum and the maximum sum together
List res = new List();
res.Add(idx);
res.Add(maxSum);
return res;
}
// Driver code
public static void Main(String[] args)
{
N = 5;
int[,] mat = {
{ 1, 2, 3, 4, 5 },
{ 5, 3, 1, 4, 2 },
{ 5, 6, 7, 8, 9 },
{ 0, 6, 3, 4, 12 },
{ 9, 7, 12, 4, 3 },
};
List ans = colMaxSum(mat);
Console.WriteLine("Row "+ (ans[0]+1)+ " has max sum "
+ ans[1]);
}
}
// This code has been contributed by 29AjayKumar Javascript
输出：
Row 3 has max sum 35如果您希望与专家一起参加现场课程，请参阅DSA 现场工作专业课程和学生竞争性编程现场课程。