Some Algorithm

2019-08-01

这里放了一些小功能的实现

adjacent_find 查找相邻元素

参考代码如下：

#include<list>
#include<algorithm>
#include<iostream>
using namespace std;

bool Equal ( int x , int y ){
	return  ( x - y ) % 2 == 0 ? 1 : 0 ;
} 

int main(){
	list < int > l ; 
	l.push_back(93); 
	l.push_back(5); 
	l.push_back(2); 
	l.push_back(2); 
	l.push_back(33); 
	l.push_back(52); 
	l.push_back(12);
	
	list < int > :: iterator i = adjacent_find ( l.begin() , l.end() ) ;
	if(i!=l.end()){
		cout<<*i<<' ';
		i++;
		cout<<*i<<' ';
	}
	
	cout<<'\n';
	
	list < int > :: iterator ii = adjacent_find ( l.begin() , l.end() , Equal ) ;
	if(ii!=l.end()){
		cout<<*ii<<' ';
		ii++;
		cout<<*ii<<' ';
	}
	return 0;
}

find_first_of查找第一个匹配字符

参考代码如下：

#include<list>
#include<algorithm>
#include<iostream>
#include<cstring>
using namespace std ; 
int main (  )  { 
	char * s1 = "abcdefu7ghijklmn" ; 
	char * s2 = "zyx3yu7ys" ; 
	char * i = find_first_of ( s1 , s1 + strlen ( s1 ) , s2 , s2 + strlen ( s2 ) ) ;
	cout<<" first word of s1 appear in s2 ' s is : " << *i << endl ;
	return 0 ;
}

count 统计个数

参考代码如下：

#include<list>
#include<algorithm>
#include<iostream>
using namespace std ; 
int main (  )  { 
	list < int > l ; 
	for ( int i = 0 ; i < 100 ; i ++ ) { 
		l.push_back ( i % 20 ) ; 
	} 
	int num = count ( l.begin() , l.end() , 9 ) ;
	cout << num ; 
	return 0 ;
}

堆排序

#include<vector>
#include<algorithm>
#include<iostream>
using namespace std;

void print ( int x ) { 
	printf(" %3d ", x ) ;
} 

int main(){
	vector < int > v ; 
	 v.push_back ( 10 ) ; 
	 v.push_back ( 9 ) ; 
	 v.push_back ( 12 ) ; 
	 v.push_back ( 1 ) ; 
	 v.push_back ( 4 ) ; 
	 v.push_back ( 3 ) ; 
	 v.push_back ( 111 ) ; 
	 v.push_back ( 7 ) ; 
	 v.push_back ( 9 ) ; 
	 
	for_each( v.begin() , v.end() , print ) ;
	cout<<endl;
	
	make_heap ( v.begin ( ) , v.end( ) ) ;
	
	for_each( v.begin() , v.end() , print ) ;
	cout<<endl;
	
	sort_heap ( v.begin ( ) , v.end( ) ) ;
	
	for_each( v.begin() , v.end() , print ) ;
	cout<<endl;
	
	return 0;
}

sort排序算法

#include<functional>
#include<algorithm>
#include<iostream>
#include<vector>

using namespace std;

void print ( int x ){
	cout<<x<<' ';
}

int main(){
	int a[]={-1,9,-34,100,45,2,98,32};
	const int len = sizeof(a)/sizeof(int);
	sort(a,a+len);
	for_each(a,a+len,print);
	cout<<endl;
	
	sort(a,a+len,greater<int>());
	for_each(a,a+len,print);
	cout<<endl;
	return 0;
}

归并算法 merge

#include<vector>
#include<algorithm>
#include<iostream>
using namespace std ;
 
 void print(int x){
 	cout<<x<<' ';
 }
 
int main(){
	int a[]={2,3,5,12};
	int b[]={9,81,711,5111,31111};
	int result [9];
	
	merge(a,a+4,b,b+5,result,less<int>());
	for_each(result,result+7,print);
	cout<<'\n';
	
	int c[]={9,8,7};
	int d[]={8,3,1,-1};
	
	merge(c,c+3,d,d+4,result,greater<int>());
	for_each(result,result+7,print);
	cout<<'\n';
	return 0;
}