while(i<=mid) t[k++]=a[i++]; while(j<=right) t[k++]=a[j++]; for(i=left,k=0;i<=right;i++,k++) a[i]=t[k];这段代码什么意思

这段代码是归并排序算法的一部分，目的是将已经排序好的两个子数组合并成一个有序的大数组。其中，i、j、k 和 mid 分别代表数组下标和两个子数组的中间位置，t[] 则是临时数组用于存储合并后的数组。首先将左右两个子数组中较小的数按顺序放入 t[] 数组中，最后用 t[] 数组中的数据覆盖原数组 a[] 中的数据，完成合并。

相关问题

#include<stdio.h> #include<stdlib.h> int main() { int n,a[1000]; scanf_s("%d", &n); for (int m = 0; m < n; m++) { scanf_s("%d", &a[m]); } mergesort(a, 0, n); for (int m = 0; m < n; m++) { printf("%d", a[m]); } return 0; } void merge(int *a, int low, int mid, int high) { int i, j, k = low; int b[1000] = { 0 }; i = low; j = mid + 1; while (i <= mid && j <= high) { if (a[i] <= a[j]) { b[k] = a[i++]; } else b[k] = a[j++]; k++; } while (i <= mid) b[k++] = a[i++]; while (j <= high) b[k++] = a[j++]; for (k = low; k <= high; k++) a[k] = b[k]; } void mergesort(int* a, int low, int high) { int mid = (low + high) / 2; if (low < right) { insert_mergesort(a, low, mid); insert_mergesort(a, mid + 1, high); merge(a, low, mid, high); } }修改错误

在你的代码中，有一处错误：在 `mergesort` 函数中，你使用了一个未定义的变量 `right`，正确的变量名应该是 `high`。下面是修改后的代码：

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

void merge(int *a, int low, int mid, int high) {
    int i, j, k = low;
    int b[1000] = { 0 };
    i = low;
    j = mid + 1;
    while (i <= mid && j <= high) {
        if (a[i] <= a[j]) {
             b[k] = a[i++];
        } else {
            b[k] = a[j++];
        }
        k++;
    }
    while (i <= mid) {
        b[k++] = a[i++];
    }
    while (j <= high) {
        b[k++] = a[j++];
    }
    for (k = low; k <= high; k++) {
        a[k] = b[k];
    }
}

void mergesort(int* a, int low, int high) {
    int mid = (low + high) / 2;
    if (low < high) { // 修正错误：将 right 改为 high
        mergesort(a, low, mid);
        mergesort(a, mid + 1, high);
        merge(a, low, mid, high);
    }
}

int main() {
    int n, a[1000];
    scanf_s("%d", &n);
    for (int m = 0; m < n; m++) {
        scanf_s("%d", &a[m]);
    }
    mergesort(a, 0, n - 1);
    for (int m = 0; m < n; m++) {
        printf("%d ", a[m]);
    }
    return 0;
}

注意，还有一个小问题：在输出数组元素时，你应该在每个元素之间加一个空格，否则输出的结果将会是连在一起的。

#include <stdio.h>#include <stdlib.h>void merge(int *a, int low, int mid, int high) { int i, j, k = low; int b[1000] = { 0 }; i = low; j = mid + 1; while (i <= mid && j <= high) { if (a[i] <= a[j]) { b[k] = a[i++]; } else { b[k] = a[j++]; } k++; } while (i <= mid) { b[k++] = a[i++]; } while (j <= high) { b[k++] = a[j++]; } for (k = low; k <= high; k++) { a[k] = b[k]; }}void mergesort(int* a, int low, int high) { int mid = (low + high) / 2; if (low < high) { // 修正错误：将 right 改为 high mergesort(a, low, mid); mergesort(a, mid + 1, high); merge(a, low, mid, high); }}int main() { int n, a[1000]; scanf_s("%d", &n); for (int m = 0; m < n; m++) { scanf_s("%d", &a[m]); } mergesort(a, 0, n - 1); for (int m = 0; m < n; m++) { printf("%d ", a[m]); } return 0;}修改错误

在程序中发现一个错误，将 right 改为 high 可以修正该错误。修改后的代码如下：

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

void merge(int *a, int low, int mid, int high) {
    int i, j, k = low;
    int b[1000] = { 0 };
    i = low;
    j = mid + 1;
    while (i <= mid && j <= high) {
        if (a[i] <= a[j]) {
             b[k] = a[i++];
        } else {
            b[k] = a[j++];
        }
        k++;
    }
    while (i <= mid) {
        b[k++] = a[i++];
    }
    while (j <= high) {
        b[k++] = a[j++];
    }
    for (k = low; k <= high; k++) {
        a[k] = b[k];
    }
}

void mergesort(int* a, int low, int high) {
    int mid = (low + high) / 2;
    if (low < high) {
        mergesort(a, low, mid);
        mergesort(a, mid + 1, high);
        merge(a, low, mid, high);
    }
}

int main() {
    int n, a[1000];
    scanf_s("%d", &n);
    for (int m = 0; m < n; m++) {
        scanf_s("%d", &a[m]);
    }
    mergesort(a, 0, n - 1);
    for (int m = 0; m < n; m++) {
        printf("%d ", a[m]);
    }
    return 0;
}