c++数值算法

数值算法：能对 容器数据进行数值计算的算法。

使用数值算法要包含#include<numeric>头文件。

accumulate(first,last,data)

计算first和last范围内数据与data的总和

#include<iostream>
#include<vector>
#include<algorithm>
#include<numeric>
using namespace std;
void main()
{
	vector<int>a;
	a.push_back (64);
	a.push_back (76);
	a.push_back (27);
	a.push_back (45);
	a.push_back (52);
	a.push_back (92);
	a.push_back (36);
	for(int i=0;i<a.size();i++)
	{
		cout<<a[i]<<"  ";
	}
	cout<<endl;
	int result;
	result=accumulate(a.begin(),a.end()-2,0);			//calculation sum
	cout<<"result="<<result<<endl;
	system("pause");
}

inner_product(first1,last1,first2,data)

计算first1和last1范围内每个数据与first2容器的相应位置的数据的乘积，然后计算乘积的和与data的总和

#include<iostream>
#include<vector>
#include<algorithm>
#include<numeric>
using namespace std;
void main()
{
	vector<int>a;
	vector<int>b;
	a.push_back (6);
	a.push_back (7);
	a.push_back (2);
	a.push_back (4);
	b.push_back (5);
	b.push_back (9);
	b.push_back (3);
	b.push_back (15);
	for(int i=0;i<a.size();i++)
	{
		cout<<a[i]<<"  ";
	}
	cout<<endl;
	for(int j=0;j<b.size();j++)
	{
		cout<<b[j]<<"  ";
	}
	cout<<endl;
	int result;
	result=inner_product(a.begin(),a.end(),b.begin(),0);		//calculation product
	cout<<"result="<<result<<endl;
	system("pause");
}

partial_sum(first,last,result)

计算first和last范围内每个数与前面的所有数的和，并把结果赋值给result容器

#include<iostream>
#include<vector>
#include<algorithm>
#include<numeric>
using namespace std;
void main()
{
	vector<int>a;
	a.push_back (6);
	a.push_back (7);
	a.push_back (2);
	a.push_back (4);
	a.push_back (5);
	a.push_back (9);
	a.push_back (3);
	for(int i=0;i<a.size();i++)
	{
		cout<<a[i]<<"  ";
	}
	cout<<endl;
	int size;
	size=a.size();
	vector<int>b(size);
	partial_sum(a.begin(),a.end(),b.begin() );		//calculation partial sum
	for(int j=0;j<b.size();j++)
	{
		cout<<b[j]<<"  ";
	}
	cout<<endl;
	system("pause");
}

adjacent_difference(first,last,result)

计算first和last范围内相邻数据的差，并把得到的数赋给result容器

#include<iostream>
#include<vector>
#include<algorithm>
#include<numeric>
using namespace std;
void main()
{
	vector<int>a;
	a.push_back (6);
	a.push_back (7);
	a.push_back (2);
	a.push_back (4);
	a.push_back (5);
	a.push_back (9);
	a.push_back (3);
	for(int i=0;i<a.size();i++)
	{
		cout<<a[i]<<"  ";
	}
	cout<<endl;
	int size;
	size=a.size();
	vector<int>b(size);
	adjacent_difference(a.begin(),a.end(),b.begin() );		//calculation the difference adjacent data
	for(int j=0;j<b.size();j++)
	{
		cout<<b[j]<<"  ";
	}
	cout<<endl;
	system("pause");
}