Question

嗨我只是在寻求帮助，我写了一段快速的代码来接受一个字符数组然后将通过一个函数运行，这将删除任何重复的字符我有一个小错误，因为它没有删除最后一个这里重复的字母是我将在代码后输出的代码..

#include <iostream>

#include <fstream>

#include <ostream>

using namespace std;

const int max_num_chars=10;

void deleteRepeats(char c[], int& size);


int main()
{
    char c[]={'a','b','b','b'};
    int c_size=4;

    cout<<"This Program reads characters into a partially filled array and then delete's repeats! \n";
    cout<<"Here is the original array \n";
    for (int i=0;i<c_size;i++)
    {
        cout<<c[i]<<"\n";
    }
    deleteRepeats(c, c_size);
    cout<<"Here is the array after the deleteRepeats function! \n";
    for (int i=0;i<c_size;i++)
    {
        cout<<c[i]<<"\n";
    }
    system("pause");
    return 0;
}
void deleteRepeats(char c[],int& size)
{
    int num = size;
    int start = 0;

    while(start != num)
    {
        char test = c[start];
        for(int i = start+1; i <= num;i++)
        {
            if(test==c[i])
            {
                for(int j = i;j<num;j++)
                    {
                    c[j] = c[j+1];
                    }
                num-=1;
            }
        }
    start +=1;
    }
    size = num;
}

这是输出...... 本程序将字符读入部分填充的数组，然后删除连冠！这是原始数组一个 b b b 这是deleteRepeats函数之后的数组！一个 b b 按任意键继续。。

抱歉，我只是通过添加修复它的代码来解决这个问题

for(int j = i;j<num;j++)
                    {
                    c[j] = c[j+1];
                    }
                num-=1;
                start-=1;

Answer 1

虽然有更好的算法。在你的情况下：

在函数“deleteRepeats”中，在循环内部“for（int i = start + 1; i＆lt; = num; i ++）”

当你删除下一个相同的元素时，你正在考虑'i'，而不考虑现在在同一个'i'，删除后也可能有重复的元素。

解决方案：删除元素后，也减少i的值。所以现在你的循环看起来像这样

for(int i = start+1; i <= num;i++)
    {
        if(test==c[i])
        {
            for(int j = i;j<num;j++)
                {
                c[j] = c[j+1];
                }
            num-=1;
          // correction
            i--;
          // correction
        }
    }

如果您有任何问题，请回复......

Answer 2

为什么只需要一个嵌套循环？

void deleteRepeats(char c[], int& size) {
    // Trivial case of empty array: do nothing.
    if(size <= 0) // Why is `size` a signed `int` and not `size_t`?
        return;

    // First character is automatically not a repetition.
    // So for each character from the second onward,
    // move it if it is different from the previous character,
    // otherwise skip over it.
    char* read = c + 1;
    char* write = read;
    char* end = c + size;
    char prev = *c;
    while(read != end) {
        if(*read != prev) {
            prev = *read;
            *write++ = prev;
        }
        ++read;
    }

    // Finish up.
    size = write - c;
}

C ++ Char Array删除重复的字符

2 个答案: