如何生成重复字符的排列 [英] How to Generate Permutations With Repeated Characters
问题描述
我基本上想创建由三个操作符号组成的字符串（例如： + - * 或 ++ / 或 +++ ）。这些字符串中的每一个都应该被推入 vector< string> opPermutations
这是我的代码到目前为止：
//设置操作符的排列
string operatorBank [4] = {+， - ，*，/};
do {
string currentPerm = operatorBank [0] + operatorBank [1] + operatorBank [2] + operatorBank [3];
this - > opPermutations.push_back（currentPerm）;
} while（std :: next_permutation（operatorBank，operatorBank + 4））;
推送到向量中的置换（作为字符串）是：
+ - * /
+ - / *
+ / * -
+ / - *
- * + /
- * / +
- + * /
- + / *
- / * +
- / + *
/ * + -
/ * - +
/ + * -
/ + - *
/ - * +
/ - + *
我想要的是我的排列如下：
- 每个字符的长度应为三个字符
- 每个可能的排列，包括字符重复一次以上的排列必须存在。
我希望它是这样组织的：
+++
---
***
///
/ * /
+ - +
++ *
** /
等...
如何实现？
使用递归打印您提出的问题。使它适应存储在向量中的排列字符串应该是微不足道的。我不是一个c ++程序员，所以在C ++中可能有更好的方法。但这里的主要思想是使用递归。
#include< iostream>
#include< string>
#include< math.h>
#include< stdio.h>
#include< stdlib.h>
using namespace std;
void displayPermutation（string permutation []，int length）{
int i;
for（i = 0; i
}
cout<< endl
}
void getPermutations（string operatorBank []，int operatorCount，
string permutation []，int permutationLength，int curIndex）{
int i;
//停止递归条件
if（curIndex == permutationLength）{
displayPermutation（permutation，permutationLength）;
}
else {
for（i = 0; i
getPermutations（operatorBank，operatorCount，permutation，
permutationLength，curIndex + 1）;
}
}
}
int main（）
{
int operatorCount = 4;
int permutationLength = 3;
string operatorBank [] = {+， - ，*，/};
string permutation [] = {，，，}; //空字符串
int curIndex = 0;
getPermutations（operatorBank，operatorCount，permutation，
permutationLength，curIndex）;
return 0;
}
输出：
+++
++ -
++ *
++ /
+ - +
+ -
+ - *
+ - /
+ * +
+ * -
+ **
+ * /
+ / + $ b b +/-
+ / *
+ //
。
。
等。
I basically want to create strings that consist of three operation symbols (eg: +-* or ++/ or +++). Each one of these strings should be pushed into vector <string> opPermutations
This is my code so far:
// Set up permutations for operators
string operatorBank[4] = {"+","-","*","/"};
do {
string currentPerm = operatorBank[0] + operatorBank[1] + operatorBank[2] + operatorBank[3];
this -> opPermutations.push_back(currentPerm);
} while ( std::next_permutation(operatorBank, operatorBank + 4) );
The permutations that are pushed into the vector (as strings) are:
+-*/
+-/*
+/*-
+/-*
-*+/
-*/+
-+*/
-+/*
-/*+
-/+*
/*+-
/*-+
/+*-
/+-*
/-*+
/-+*
What I want however is to have my permutations exist like this:
- Each should be three characters in length
- Every possible permutation, including the ones in which a character is repeated more than one time, must be present.
I want it to be organized as such:
+++
---
***
///
/*/
+-+
++*
**/
etc...
How can I achieve this?
Using the recursion to print what you asked. Adapting it to store permutation string in vectors should be trivial. I am not a c++ programmer,so there may be better way to do it in C++. but the main idea here is to use recursion.
#include <iostream>
#include <string>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
using namespace std;
void displayPermutation(string permutation[], int length){
int i;
for (i=0;i<length;i++){
cout<<permutation[i];
}
cout << endl;
}
void getPermutations(string operatorBank[], int operatorCount,
string permutation[],int permutationLength, int curIndex){
int i;
//stop recursion condition
if(curIndex == permutationLength){
displayPermutation(permutation,permutationLength);
}
else{
for(i = 0; i < operatorCount; i++){
permutation[curIndex] = operatorBank[i];
getPermutations(operatorBank,operatorCount,permutation,
permutationLength,curIndex+1);
}
}
}
int main ()
{
int operatorCount = 4;
int permutationLength = 3;
string operatorBank[] = {"+","-","*","/"};
string permutation[] = {"","","",""}; //empty string
int curIndex = 0;
getPermutations(operatorBank,operatorCount,permutation,
permutationLength,curIndex);
return 0;
}
output:
+++
++-
++*
++/
+-+
+--
+-*
+-/
+*+
+*-
+**
+*/
+/+
+/-
+/*
+//
.
.
and so on.
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