#include <stdio.h>
#include <time.h>

// 应用3x3 GaussianBlur到给定的二维数组src上，并将结果存到二维数组dst中
void applyGaussianBlur(float src[][5], float dst[][5], int h, int w, float kernel[3][3]) {
    int i, j;  // 在函数开头声明循环变量，符合C89要求
    for (i = 1; i < h - 1; ++i) {
        for (j = 1; j < w - 1; ++j) {
            dst[i][j] = 
                src[i - 1][j - 1] * kernel[0][0] + src[i - 1][j] * kernel[0][1] + src[i - 1][j + 1] * kernel[0][2] +
                src[i][j - 1] * kernel[1][0] + src[i][j] * kernel[1][1] + src[i][j + 1] * kernel[1][2] +
                src[i + 1][j - 1] * kernel[2][0] + src[i + 1][j] * kernel[2][1] + src[i + 1][j + 1] * kernel[2][2];
        }
    }
}

int main() {
    float inputImage[5][5] = {
        {1, 2, 3, 4, 5},
        {6, 7, 8, 9, 10},
        {11, 12, 13, 14, 15},
        {16, 17, 18, 19, 20},
        {21, 22, 23, 24, 25}
    };
    float kernel[3][3] = {
        {1.0f / 16, 2.0f / 16, 1.0f / 16},
        {2.0f / 16, 4.0f / 16, 2.0f / 16},
        {1.0f / 16, 2.0f / 16, 1.0f / 16}
    };
    float outputImage[5][5];
    int i, j;  // 在函数开头声明循环变量，符合C89要求

    // 计时开始
    clock_t start_time = clock();

    applyGaussianBlur(inputImage, outputImage, 5, 5, kernel);

    // 计时结束
    clock_t end_time = clock();
    double elapsed_time = ((double)(end_time - start_time)) / CLOCKS_PER_SEC;

    // 输出结果矩阵
    printf("经过GaussianBlur后的图像矩阵：\n");
    for (i = 0; i < 5; ++i) {
        for (j = 0; j < 5; ++j) {
            printf("%.2f ", outputImage[i][j]);
        }
        printf("\n");
    }

    // 输出运行时间
    printf("运行时间：%.6f 秒\n", elapsed_time);

    return 0;
}