AC diary--Vector dot product calculation Openjudge 1.6 09

09: Vector dot Product calculation

Total time limit:

1000ms

Memory Limit:

65536kB

Describe

In linear algebra and computational geometry, the vector dot product is a very important operation.

Given two n-dimensional vectors a= (a1,a2,..., an) and b= (B1,b2,..., bn), find dot product a· b=a1b1+a2b2+...+anbn.

Input

The first line is an integer n. 1 <= n <= 1000.
The second line contains n integers a1,a2,..., an.
The third line contains n integers b1,b2,..., bn.
Adjacent integers are separated by a single space. The absolute value of each integer is no more than 1000.

Output

An integer, which is the dot product result of two vectors.

Sample input

31 4 62) 1 5

Sample output

36

Ideas:

Simulation

Come on, on the code:

#include <iostream>using namespacestd;Long Long intn,a[1001],b[1001],ans=0;intMain () {CIN>>N;  for(intI=1; i<=n;i++) cin>>A[i];  for(intI=1; i<=n;i++) cin>>B[i];  for(intI=1; i<=n;i++) ans+=a[i]*B[i]; cout<<ans<<Endl; return 0;}

AC diary--Vector dot product calculation Openjudge 1.6 09