矩阵中出现频率最高的元素

Question

我需要找到矩阵中出现频率最高的元素，并打印出来。如果有不止一个最频繁出现的元素，程序应该打印其中最小的一个。

如何在矩阵（二维数组）中实现查找一维数组最大元素的代码？

#include <stdio.h>

void main() {
  int i, j, k = 0, m = 3, n = 4, vel = 8, count = 0, maxCount = 0;
  double mat[3][4], maxElement, arr[100] = { 1.3, 4.2, 1.3, 5, 4.2, 6.8, 3.7 };

  for (i = 0; i < m; i++)
    for (j = 0; j < n; j++)
      scanf("%lf", &mat[i][j]);
  for (i = 0; i < vel; i++) {
    for (j = i + 1; j < vel; j++) {
      if (arr[i] == arr[j]) {
        count++;
        if (count > maxCount)
          maxElement = arr[j];
      }
    }
  }
  printf("Most frequent is: %g", maxElement);
}

Answer 1

你的算法不适用于一维矩阵，但一旦固定，它可以用于二维矩阵不变：

#include <stdio.h>

double find_most_frequent(const double *arr, size_t vel) {
    size_t i, j, maxcount = 0, mostfreq = 0;
    
    for (i = 0; i < vel; i++) {
        size_t count = 1;
        for (j = i + 1; j < vel; j++) {
            if (arr[i] == arr[j]) {
                count++;
        }
        if (maxcount < count || (maxcount == count && arr[mostfreq] > arr[i])) {
            maxcount = count;
            mostfreq = i;
        }
    }
    return arr[mostfreq];
} 

#define ROWS  3
#define COLS  4

int main() {
    double mat[ROWS][COLS];
    double arr[] = { 1.3, 4.2, 1.3, 5, 4.2, 6.8, 3.7 };

    for (int i = 0; i < ROWS; i++) {
        for (int j = 0; j < COLS; j++) {
            if (scanf("%lf", &mat[i][j]) != 1)
                return 1;
        }
    }
    printf("Most frequent in array is: %g\n", find_most_frequent(arr, sizeof(arr) / sizeof(arr[0]));
    printf("Most frequent in matrix is: %g\n", find_most_frequent(&mat[0][0], sizeof(mat) / sizeof(mat[0][0]));
    return 0;
}

矩阵中出现频率最高的元素

Most frequent element in matrix

c

arrays

matrix