如何找到元素的索引（以及其他一些东西）

Question

我正在编写一个代码，它将一些随机的 17 个字符串替换为一个字母表，但我找不到方法。基本上，我想做的是：

char strings[] = {
    "L-nIbhm5<z:92~+,x",
    "9bC5f0q@qA(RKZ>|r",
    "9bC5f0q@qA(RKZ>|r",
    "k=5,ln(08IAl(gGAK",
    "|N,8]dGu)'^MaYpu[",
    "!&,Y*nz8C*,J}{+d]",
    "Us9%^%?n5!~e@@*+@",
    "zF8,1KV#¥]$k?|9R#",
    "0B4>=nioEjp>4rhgi",
}

char alphabet[]{
    "a","b","c","d","e","f","g","h","i",
}

replace(std::string str){
    /**get str and then see the index of the corresponding string in strings[], and replace the string with alphabet[index number], while deleting the original string part that was replaced**/

int main(){
    cin >> std::string replace;
    replace(replace);

示例输入：L-nIbhm5<z:92~+,x9bC5f0q@qA(RKZ>|r9bC5f0q@qA(RKZ>|r

预期输出：abc

编辑： 新代码 对原代码的改动

它还有一个比简化版本（以前的代码）更大的数组。它显示了整个程序的结构。（字符串被路由到哪里以及为什么）

基本上它在做什么

从用户那里得到输入，放入输入变量中，输入经过算法（）函数不变，然后进入替换函数并被替换。然后，被替换的字符串通过原始路由返回到主函数，并在其中显示。

我将数组保留为字符串类型，因为 const char* 给了我一个分段错误。

std::string Subs[53]=
{
    "LQlMv]G5^^1kcm?fk",
    "7W^S;/vB(6%I|w[fl",
    "<w7>4f//Z55ZxK'z.",
    "_W5g(lu<pTu3^_A7n",
    "OfLm%8:EF}0V1?BSS",
    "|+E6t,AZ~XewXP17T",
    "L-nIbhm5<z:92~+,x",
    "L-nIbhm5<z:92~+,x",
    "9bC5f0q@qA(RKZ>|r",
    "9bC5f0q@qA(RKZ>|r",
    "k=5,ln(08IAl(gGAK",
    "|N,8]dGu)'^MaYpu[",
    "!&,Y*nz8C*,J}{+d]",
    "Us9%^%?n5!~e@@*+@",
    "zF8,1KV#¥]$k?|9R#",
    "0B4>=nioEjp>4rhgi",
    "EG@0[W9.N4i~E<f3x",
    "(0Pwkk&IPchJHs.7A",
    "7XgmQ6fW<|J+NY[m0",
    ".g4CwX/DU!!~!zbtZ",
    "+_U'qn_/9Fo|gT/!n",
    "=0s(mYh&F%y=MBS5(",
    "cg71(}bo+Q5P8F[T6",
    "lc|a\%5.9pOpooU+QR",
    "E_(3A:o+.]qL3MYA6",
    "H@O'X_RiVS@8l0bKD",
    "Y1gbGD`~8d>HSWN35",
    "LQlMv]G5^^1kcm?fk",
    "T4}gI;`BFVfhw=-sf",
    "6BHMA0IRix]/=(jht",
    "yS$=@Jdpp?P2k6SMQ",
    "t1~|kkh+>4d>}OQ`a",
    "2Y-\\CU\"944yBluWD5",
    "'M\\ZbIX5{`Xd;qi!o",
    "?N+RtVqj_r(C5@#0\"",
    "2;*Livh?V$X/8z@Md",
    ")IN|7FOs2l-mAM[d@",
    "(~f268J},xXrK'Rp'",
    "&r/qf9fFHnzV!RzH/",
    "}naDRH4p$NI2a).t,",
    "{8DM+7!.Mge|~fnO|",
    ")r[@nI0YDH>6cE38p",
    "(0Pwkk&IPchJHs.7A",
    ")r[@nI0YDH>6cE38p",
    "8M-=cQFQ,pPo7eu=p",
    "0PHw=/|(tZ1}FHm/'",
    "[su`'0Oybc.\"-/W5)",
    "1uHl[IC7Sr#NUJV;I",
    "8z8%,jK0CDOkJz8I?",
    "3Ao2yXDN%YzpE&Suy",
    "zNs`7E'e/$i8VqaUL",
    "bzHmA^K2>7`UZ?!AO",
};

std::string Alphabet[53] = 
{
    " ","a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","r","w","x","y","z",
    "A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z",
};


std::string replace(std::string rep) {
    int len = sizeof(Subs)/sizeof(Subs[0]);
    std::stringstream ss1;
    for(int i = 0; i < len; i++) {
        if (rep.find(Subs[i]) != std::string::npos) {
            ss1 << Subs[i];
        }
    }
    std::string input = ss1.str();
    return input;
}

std::string algorithm(std::string input)
{
    //some other algorithms come here(not relative to this question)
    input = replace(input);
    return input;
}

int main(void){
    int ed;
    std::cin >> ed;

    if(ed == 1){
//different function(not relative to the question)
        }
    else if(ed == 0){
        std::string input;
        std::cin >> input;
        input = algorithm(input);
        std::cout << input << std::endl;
    }

    else{
        std::cout << "1 or 0" << std::endl;
        main();
    }

return 0;
}

示例输入：L-nIbhm5<z:92~+,x9bC5f0q@qA(RKZ>|r9bC5f0q@qA(RKZ>|r

预期输出：abc

实际输出：L-nIbhm5<z:92~+,xL-nIbhm5<z:92~+,x9bC5f0q@qA(RKZ>|r9bC5f0q@qA(RKZ>|r

对不起，它变长了。

Answer 1

上面的代码有几个错误：

• char array 初始化不正确。
• method body 用于 main 和 replace 方法不是 closed。
• 目前replace方法的默认返回类型为int。

这里有string#find 方法可以提供帮助。

我已尝试进行这些修复，这里是 C++17 中的更新代码：

#include <iostream>
#include <sstream>
using namespace std;

const char *strings[9] = {
    "L-nIbhm5<z:92~+,x",
    "9bC5f0q@qA(RKZ>|r",
    "9bC5f0q@qA(RKZ>|r",
    "k=5,ln(08IAl(gGAK",
    "|N,8]dGu)'^MaYpu[",
    "!&,Y*nz8C*,J}{+d]",
    "Us9%^%?n5!~e@@*+@",
    "zF8,1KV#¥]$k?|9R#",
    "0B4>=nioEjp>4rhgi"
};

const char *alphabet[9] = {
    "a","b","c","d","e","f","g","h","i"
};

void replace(std::string rep) {
    int len = sizeof(strings)/sizeof(strings[0]);
    std::stringstream ss1;
    for(int i = 0; i < len; i++) {
        if (rep.find(strings[i]) != std::string::npos) {
            ss1 << alphabet[i];
        }
    }
    std::cout << ss1.str();
}

int main(){
    std::string rep;
    cin >> rep;
    replace(rep);
}

供参考：https://onlinegdb.com/Bd9DXSPAa

注意-以上代码仅供参考，请务必添加所有测试用例处理。

Answer 2

我为您的代码制作了一个 c++17 版本。 用 C++ 风格的容器、迭代器替换 'c' 风格的数组和指针。 并使用 std::string::replace 函数。如果可以，请使用标准库， 它经过测试并有据可查。

#include <algorithm>
#include <iostream>
#include <regex>
#include <string>
#include <vector>

// std::vector/std::array instead of 'c' style arrays.
// allows us to us range based for loops later.
std::vector<std::string> strings =
{
        "L-nIbhm5<z:92~+,x",
        "9bC5f0q@qA(RKZ>|r",
        "k=5,ln(08IAl(gGAK",
        "|N,8]dGu)'^MaYpu[",
        "!&,Y*nz8C*,J}{+d]",
        "Us9%^%?n5!~e@@*+@",
        //"zF8,1KV#¥]$k?|9R#", // <<== I commented out this line, ¥ is not a valid charcter in my environment
        "0B4>=nioEjp>4rhgi"
};

// a string is already an array of characters.
std::string alphabet{ "abcdefghijkl" };

std::string replace_with_alphabet(const std::string& input)
{
    std::string retval{ input };
    std::size_t index{ 0 };

    // range based for, it will keep the order of the vector.
    for (const auto& str : strings)
    {
        // look if you can find any of the predefined strings 
        // in the input strings.
        const size_t pos = retval.find(str, 0);

        // if found
        if (pos != std::string::npos) 
        {
            // get the next character from the alphabet
            std::string replacement{ alphabet[index++] };

            // use std::string::replace for replacing the substring
            const size_t len = str.length();
            retval.replace(pos, len, replacement, 0);
        }
    }

    return retval;
};

/**get str and then see the index of the corresponding string in strings[], and replace the string with alphabet[index number], while deleting the original string part that was replaced**/
int main()
{
    auto output = replace_with_alphabet("L-nIbhm5<z:92~+,x9bC5f0q@qA(RKZ>|rk=5,ln(08IAl(gGAK");
    std::cout << output << std::endl;
}