我在尝试从C ++库中找出排序函数并尝试从a-z对这个字符串数组进行排序时遇到了很多麻烦,请帮助!
我被告知要使用它,但我无法弄清楚我做错了什么。
// std::sort(stringarray.begin(), stringarray.end());
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main()
{
int z = 0;
string name[] = {"john", "bobby", "dear",
"test1", "catherine", "nomi",
"shinta", "martin", "abe",
"may", "zeno", "zack", "angeal", "gabby"};
sort(name[0],name[z]);
for(int y = 0; y < z; y++)
{
cout << name[z] << endl;
}
return 0;
}
答案 0 :(得分:27)
算法使用迭代器到序列的开头和结尾。也就是说,您想要调用std::sort()
这样的内容:
std::sort(std::begin(name), std::end(name));
如果你不使用C ++ 11并且你没有std::begin()
和std::end()
,他们很容易自己定义(显然不在命名空间{{1} }}):
std
答案 1 :(得分:11)
int z = sizeof(name)/sizeof(name[0]); //Get the array size
sort(name,name+z); //Use the start and end like this
for(int y = 0; y < z; y++){
cout << name[y] << endl;
}
修改:
考虑所有“正确”的命名约定(根据评论):
int N = sizeof(name)/sizeof(name[0]); //Get the array size
sort(name,name+N); //Use the start and end like this
for(int i = 0; i < N; i++){
cout << name[i] << endl;
}
注意:DietmarKühl的答案最好,std::begin()
&amp; std::end()
应该与{+ 1}}类似的函数用于C ++ 11,否则可以定义它们。
答案 2 :(得分:8)
使用std :: vector
的示例#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
int main()
{
/// Initilaize vector using intitializer list ( requires C++11 )
std::vector<std::string> names = {"john", "bobby", "dear", "test1", "catherine", "nomi", "shinta", "martin", "abe", "may", "zeno", "zack", "angeal", "gabby"};
// Sort names using std::sort
std::sort(names.begin(), names.end() );
// Print using range-based and const auto& for ( both requires C++11 )
for(const auto& currentName : names)
{
std::cout << currentName << std::endl;
}
//... or by using your orignal for loop ( vector support [] the same way as plain arrays )
for(int y = 0; y < names.size(); y++)
{
std:: cout << names[y] << std::endl; // you were outputting name[z], but only increasing y, thereby only outputting element z ( 14 )
}
return 0;
}
这完全避免使用普通数组,并允许您使用std :: sort函数。您可能需要更新编译器以使用= {...}
您可以使用vector.push_back("name")
答案 3 :(得分:4)
你的循环没有做任何事情,因为你的计数器z
是0(0 <0评估为false
,所以循环永远不会开始)。
相反,如果你有权访问C ++ 11(你真的应该以此为目标!)尝试使用迭代器,例如:通过使用非成员函数std::begin()
和std::end()
,以及范围for循环来显示结果:
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main()
{
int z = 0;
string name[] = {"john", "bobby", "dear", "test1", "catherine", "nomi", "shinta", "martin", "abe", "may", "zeno", "zack", "angeal", "gabby"};
sort(begin(name),end(name));
for(auto n: name){
cout << n << endl;
}
return 0;
}
答案 4 :(得分:2)
这对我有用:
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main() {
string name[] = {"john", "bobby", "dear", "test1", "catherine", "nomi", "shinta", "martin", "abe", "may", "zeno", "zack", "angeal", "gabby"};
int sname = sizeof(name)/sizeof(name[0]);
sort(name, name + sname);
for(int i = 0; i < sname; ++i)
cout << name[i] << endl;
return 0;
}
答案 5 :(得分:2)
正如许多人所说,你可以使用std :: sort进行排序,但是当你例如想要从z-a排序时会发生什么?这段代码可能很有用
bool cmp(string a, string b)
{
if(a.compare(b) > 0)
return true;
else
return false;
}
int main()
{
string words[] = {"this", "a", "test", "is"};
int length = sizeof(words) / sizeof(string);
sort(words, words + length, cmp);
for(int i = 0; i < length; i++)
cout << words[i] << " ";
cout << endl;
// output will be: this test is a
}
如果要颠倒排序顺序,只需修改cmp函数中的符号。
希望这有用:)
干杯!!!
答案 6 :(得分:1)
多集合容器使用红黑树来保持元素排序。
// using the multiset container to sort a list of strings.
#include <iostream>
#include <set>
#include <string>
#include <vector>
std::vector<std::string> people = {
"Joe",
"Adam",
"Mark",
"Jesse",
"Jess",
"Fred",
"Susie",
"Jill",
"Fred", // two freds.
"Adam",
"Jack",
"Adam", // three adams.
"Zeke",
"Phil"};
int main(int argc, char **argv) {
std::multiset<std::string> g(people.begin(), people.end()); // """sort"""
std::vector<std::string> all_sorted (g.begin(), g.end());
for (int i = 0; i < all_sorted.size(); i++) {
std::cout << all_sorted[i] << std::endl;
}
}
示例输出:
Adam
Adam
Adam
Fred
Fred
Jack
Jess
Jesse
Jill
Joe
Mark
Phil
Susie
Zeke
注意,优点是多重插入在插入和删除后保持排序,非常适合显示活动连接或不显示。
答案 7 :(得分:0)
我们可以使用sort()函数对字符串数组进行排序。
程序:
首先确定大小字符串数组。
使用排序功能。 sort(array_name,array_name + size)
通过字符串数组/
代码段
#include<bits/stdc++.h>
using namespace std;
int main()
{
ios::sync_with_stdio(false);
string name[] = {"john", "bobby", "dear", "test1", "catherine", "nomi", "shinta", "martin", "abe", "may", "zeno", "zack", "angeal", "gabby"};
int len = sizeof(name)/sizeof(name[0]);
sort(name, name+len);
for(string n: name)
{
cout<<n<<" ";
}
cout<<endl;
return 0;
}
答案 8 :(得分:-2)
我的解决方案与上述任何一种解决方案略有不同,因为我刚刚运行它。因此感兴趣:
#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
using namespace std;
int main() {
char *name[] = {"john", "bobby", "dear", "test1", "catherine", "nomi", "shinta", "martin", "abe", "may", "zeno", "zack", "angeal", "gabby"};
vector<string> v(name, name + 14);
sort(v.begin(),v.end());
for(vector<string>::const_iterator i = v.begin(); i != v.end(); ++i) cout << *i << ' ';
return 0;
}