在尝试使用冒泡排序后,我尝试将2D数组重置为其原始形式。我需要将它重置回排序之前的状态。我该怎么做?如果你有一个问题,为什么数组是全局的。这是一项学校任务,这就是我们的教授希望我们这样做的方式。这是我的计划:
#include<iostream>
using namespace std;
const int NUM_COLS=4;
const int NUM_ROWS=5;
int array[NUM_ROWS][NUM_COLS]={{5, 3, 2, 16},
{9, 8, 10, 17},
{4, 7, 11, 18},
{2, 5, 9, 12},
{7, 9, 4, 10}};
它使用bubbleSort对数组进行排序
void bubbleSort(int row, int col){}
它是显示数组函数头
void displayArray(){}
这是主要功能
int main(){
cout<<"original array"<<endl;
displayArray();
bubbleSort(NUM_ROWS-1, NUM_COLS);
cout<<"\nbubble sort"<<endl;
displayArray();
reset();
displayArray();
return 0;
}
现在我需要将数组重置为原始数据。我做了这个,但它不起作用。
void reset(){
int array[NUM_ROWS][NUM_COLS]={{5, 3, 2, 16},
{9, 8, 10, 17},
{4, 7, 11, 18},
{2, 5, 9, 12},
{7, 9, 4, 10}};
}
你的reset
正在声明一个新阵列(并且不做任何事情)。你不能分配(=
)C风格数组,所以你需要看起来不同的东西。如果你可以使用std::array
,你可以在reset
中分配。
#include <array>
const int NUM_COLS=4;
const int NUM_ROWS=5;
std::array<std::array<int, NUM_ROWS>, NUM_COLS> values = {
{5, 3, 2, 16},
{9, 8, 10, 17},
{4, 7, 11, 18},
{2, 5, 9, 12},
{7, 9, 4, 10}};
// Other code probably remains unchanged
void reset() {
values = {
{5, 3, 2, 16},
{9, 8, 10, 17},
{4, 7, 11, 18},
{2, 5, 9, 12},
{7, 9, 4, 10}};
}
在这一点上,你注意到你的边界是错误的,它应该是
const int NUM_COLS=5;
const int NUM_ROWS=4;
或者不同形状的阵列初始化器。
void reset(){
static int original[NUM_ROWS][NUM_COLS]={{5, 3, 2, 16},
{9, 8, 10, 17},
{4, 7, 11, 18},
{2, 5, 9, 12},
{7, 9, 4, 10}};
for (int i = 0; i < NUM_ROWS; i++)
memcpy(array[i], original[i], NUM_COLS * sizeof(int));
}
不是最漂亮的东西,但这应该有效。既然你的教授希望你这样做,那就去吧_ \ _(ツ)_ /¯
正如我在评论中所说,分配数组的最简单方法是将它们包装在一个结构中。 Voilà,突然C ++开发了它甚至不知道它继承自C和复制数组的能力!1甚至是嵌套的多维数组!
#include <iostream>
#include <iomanip>
#include <algorithm>
using namespace std;
const int NUM_COLS=4;
const int NUM_ROWS=5;
// Define a struct (i.e., a class with all public members)
// which has just a single member, the array. Note that this is
// only a *type* declaration, no object is created yet.
struct arrT
{
int array [NUM_ROWS][NUM_COLS];
};
// object creation.
arrT workArr;
void reset()
{
// The initialization value is hidden inside the function.
// static variables are initialized only once, for constant
// data at compile time.
static const arrT oriArr
{
{ {5, 3, 2, 16},
{9, 8, 10, 17},
{4, 7, 11, 18},
{2, 5, 9, 12},
{7, 9, 4, 10}
}
};
workArr = oriArr; // simple default assignment of structs
}
// The parameters are redundant.
void stdSort(int /*row*/, int /*col*/)
{
// Sort the 2D array as a one-dimensional sequence
// (which the elements are in memory).
// The algorithm expects iterators to the first and
// one-after-the-last elements in the sequence. Pointers
// to the elements in an array are perfectly good iterators.
std::sort(&workArr.array[0][0], &workArr.array[NUM_ROWS-1][NUM_COLS]);
}
void displayArray()
{
// The top-level elements of a 2D array are the rows...
for(auto &row: workArr.array)
{
// ... and the elements of the rows are ints.
// Note how the
// dimensions are known from the class declaration.
for(auto &el: row)
{
cout << setw(4) << el;
}
cout << "\n";
}
}
int main(){
cout << "Work array before initialization:\n";
displayArray();
reset(); // before, the values of the global array are 0.
cout<<"\nWork array after init:\n";
displayArray();
stdSort(NUM_ROWS, NUM_COLS);
cout<<"\nWork array after std sort"<<endl;
displayArray();
reset();
cout << "\nWork array after reset\n";
displayArray();
return 0;
}