1、直接在函数中实现矩阵加法

最简单直接的方法，在一个函数使用for循环中对矩阵进行操作。

#include <stdio.h>

#define ROWS 3
#define COLS 3

void addMatrices(int mat1[ROWS][COLS], int mat2[ROWS][COLS], int result[ROWS][COLS]) {
    for (int i = 0; i < ROWS; i++) {
        for (int j = 0; j < COLS; j++) {
            result[i][j] = mat1[i][j] + mat2[i][j];
        }
    }
}

int main() {
    int mat1[ROWS][COLS] = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
    int mat2[ROWS][COLS] = {{9, 8, 7}, {6, 5, 4}, {3, 2, 1}};
    int result[ROWS][COLS];

    addMatrices(mat1, mat2, result);

    printf("结果:\n");
    for (int i = 0; i < ROWS; i++) {
        for (int j = 0; j < COLS; j++) {
            printf("%d ", result[i][j]);
        }
        printf("\n");
    }

    return 0;
}

2、使用指针实现矩阵加法

通过指针来操作数组，进行矩阵加法。

#include <stdio.h>

#define ROWS 3
#define COLS 3

void addMatrices(int *mat1, int *mat2, int *result, int rows, int cols) {
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            *(result + i * cols + j) = *(mat1 + i * cols + j) + *(mat2 + i * cols + j);
        }
    }
}

int main() {
    int mat1[ROWS][COLS] = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
    int mat2[ROWS][COLS] = {{9, 8, 7}, {6, 5, 4}, {3, 2, 1}};
    int result[ROWS][COLS];

    addMatrices((int *)mat1, (int *)mat2, (int *)result, ROWS, COLS);

    printf("结果:\n");
    for (int i = 0; i < ROWS; i++) {
        for (int j = 0; j < COLS; j++) {
            printf("%d ", result[i][j]);
        }
        printf("\n");
    }

    return 0;
}

3、使用动态内存分配实现矩阵加法

使用动态内存分配来创建矩阵，进行矩阵加法。

#include <stdio.h>
#include <stdlib.h>

void addMatrices(int **mat1, int **mat2, int **result, int rows, int cols) {
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            result[i][j] = mat1[i][j] + mat2[i][j];
        }
    }
}

int main() {
    int rows = 3, cols = 3;
    int **mat1 = (int **)malloc(rows * sizeof(int *));
    int **mat2 = (int **)malloc(rows * sizeof(int *));
    int **result = (int **)malloc(rows * sizeof(int *));

    for (int i = 0; i < rows; i++) {
        mat1[i] = (int *)malloc(cols * sizeof(int));
        mat2[i] = (int *)malloc(cols * sizeof(int));
        result[i] = (int *)malloc(cols * sizeof(int));
    }

    // Initialize matrices
    int init1[3][3] = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
    int init2[3][3] = {{9, 8, 7}, {6, 5, 4}, {3, 2, 1}};
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            mat1[i][j] = init1[i][j];
            mat2[i][j] = init2[i][j];
        }
    }

    addMatrices(mat1, mat2, result, rows, cols);

    printf("结果:\n");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("%d ", result[i][j]);
        }
        printf("\n");
    }

    // Free allocated memory
    for (int i = 0; i < rows; i++) {
        free(mat1[i]);
        free(mat2[i]);
        free(result[i]);
    }
    free(mat1);
    free(mat2);
    free(result);

    return 0;
}