系统老说unique没定义，可是我已经包含了这些头文件是不是还要什么头文件呢?

Question

#include"iostream.h"
#include<vector> 
using namespace std;

Answer 1

需求头文件: <algorithm>示例// alg_unique.cpp// compile with: /EHsc#include <vector>#include <algorithm>#include <functional>#include <iostream>#include <ostream>using namespace std;// Return whether modulus of elem1 is equal to modulus of elem2bool mod_equal ( int elem1, int elem2 ){if ( elem1 < 0 )&nbsp;elem1 = - elem1;if ( elem2 < 0 )&nbsp;elem2 = - elem2;return elem1 == elem2;};int main( ){vector <int> v1;vector <int>::iterator v1_Iter1, v1_Iter2, v1_Iter3,v1_NewEnd1, v1_NewEnd2, v1_NewEnd3;int i;for ( i = 0 ; i <= 3 ; i++ ){v1.push_back( 5 );v1.push_back( -5 );}int ii;for ( ii = 0 ; ii <= 3 ; ii++ ){v1.push_back( 4 );}v1.push_back( 7 );cout << "Vector v1 is ( " ;for ( v1_Iter1 = v1.begin( ) ; v1_Iter1 != v1.end( ) ; v1_Iter1++ )cout << *v1_Iter1 << " ";cout << ")." << endl;// Remove consecutive duplicatesv1_NewEnd1 = unique ( v1.begin ( ) , v1.end ( ) );cout << "Removing adjacent duplicates from vector v1 gives\n ( " ;for ( v1_Iter1 = v1.begin( ) ; v1_Iter1 != v1_NewEnd1 ; v1_Iter1++ )cout << *v1_Iter1 << " ";cout << ")." << endl;// Remove consecutive duplicates under the binary prediate mod_equalsv1_NewEnd2 = unique ( v1.begin ( ) , v1_NewEnd1 , mod_equal );cout << "Removing adjacent duplicates from vector v1 under the\n "<< " binary predicate mod_equal gives\n ( " ;for ( v1_Iter2 = v1.begin( ) ; v1_Iter2 != v1_NewEnd2 ; v1_Iter2++ )cout << *v1_Iter2 << " ";cout << ")." << endl;// Remove elements if preceded by an element that was greaterv1_NewEnd3 = unique ( v1.begin ( ) , v1_NewEnd2, greater<int>( ) );cout << "Removing adjacent elements satisfying the binary\n "<< " predicate mod_equal from vector v1 gives ( " ;for ( v1_Iter3 = v1.begin( ) ; v1_Iter3 != v1_NewEnd3 ; v1_Iter3++ )cout << *v1_Iter3 << " ";cout << ")." << endl;}