c++ - 如何比较两个 vector 中的两个值，然后更新 C++ 中的 vector 值？

Question

感谢您对前面代码的帮助，伙计们!我现在正在扩展以前的查询以包括此代码: 我遇到了 for 循环和 if 语句没有输出的问题。我必须比较两个 vector 中的字符串，看看一个是否是另一个的子集；如果有一个子集，我必须删除它。 (这两个 vector 实际上是相同的......这本质上是将 vector 中的所有元素相互比较)。任何指导将不胜感激!

 //headers: iostream, vector
 //namespace std 
 //main function

//each vector already has content (read from a file) stored in them. Both vectors hold         the same elements.

int c,j; string first_sequence, second_sequence;
vector<string>::iterator ivector1; vector<string>::iterator ivector2;
vector<string> sequence_1; vector<string> sequence_2; vector<string> header;

 //comparison of sequences within each element of vectors

size_t location,x,y,k,s;

k = sequence_1.size(); 
s = sequence_2.size();
for(ivector1 = sequence_1.begin(); ivector1< sequence_1.end(); ivector1++){
 for(ivector2= sequence_2.begin();ivector2<sequence_2.end(); ivector2++){
    *ivector1 = first_sequence; *ivector2 = second_sequence;    

    if(ivect1 != ivect2){
        x = first_sequence.size();
        y = second_sequence.size();

        if(x > y){
            location = first_sequence.find(second_sequence);
                                if (location != -1){
                                    cout << "Deleting the sequence with id: <"     << *ivector2 << endl;
                    sequence_2.erase(ivector2); *ivector2 = "gone";
                                     }  


                }   else if (y > x) {
            location = second_sequence.find(first_sequence);
                                if (location != -1){                             
                    cout << "Deleting the sequence with id: <"<< *ivector1 << endl;
                    sequence_1.erase(ivector1); *ivector1 = "gone";

                                    }   

                         }
    }
 }
}

return 0;
}

Answer 1

您没有得到任何输出，因为 vector1 中的所有元素都不大于您插入到 vector2 中的最小值。因此，您测试的这个 if 条件

  if (*ilist1 > *ilist2)

永远不会满足，因此不会运行 cout 语句。我愿意打赌，如果你把它改成

 if (*ilist1 < *ilist2)

您将在终端/屏幕上看到输出。 3 总是 < 4。