代码加入一个输出排完序后的数组

以下是修改后的代码，新增了一个函数用于将数组排序并输出：

#include <stdio.h>

int max(int a, int b) {
    return a > b ? a : b;
}

void merge(int arr[], int left, int mid, int right) {
    int i, j, k;
    int n1 = mid - left + 1;
    int n2 = right - mid;
    int L[n1], R[n2];
    for (i = 0; i < n1; i++)
        L[i] = arr[left + i];
    for (j = 0; j < n2; j++)
        R[j] = arr[mid + 1 + j];
    i = 0;
    j = 0;
    k = left;
    while (i < n1 && j < n2) {
        if (L[i] <= R[j]) {
            arr[k] = L[i];
            i++;
        } else {
            arr[k] = R[j];
            j++;
        }
        k++;
    }
    while (i < n1) {
        arr[k] = L[i];
        i++;
        k++;
    }
    while (j < n2) {
        arr[k] = R[j];
        j++;
        k++;
    }
}

void mergeSort(int arr[], int left, int right) {
    if (left < right) {
        int mid = left + (right - left) / 2;
        mergeSort(arr, left, mid);
        mergeSort(arr, mid + 1, right);
        merge(arr, left, mid, right);
    }
}

int findMax(int arr[], int left, int right) {
    if (left == right) {
        return arr[left];
    } else {
        int mid = (left + right) / 2;
        int leftMax = findMax(arr, left, mid);
        int rightMax = findMax(arr, mid + 1, right);
        return max(leftMax, rightMax);
    }
}

int main() {
    int arr[] = {3, 5, 1, 7, 9, 4};
    int n = sizeof(arr) / sizeof(arr[0]);
    mergeSort(arr, 0, n - 1);
    printf("The sorted array is: ");
    for (int i = 0; i < n; i++) {
        printf("%d ", arr[i]);
    }
    printf("\n");
    int maxNum = findMax(arr, 0, n - 1);
    printf("The maximum number in the array is %d\n", maxNum);
    return 0;
}

在原有代码的基础上，新增了一个归并排序的函数mergeSort，用于对数组进行排序。在主函数中调用该函数，然后输出排完序后的数组。