二维矩阵实现的多人多车求距离

#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <cmath>
using namespace std;
#define M 5000
#define N 50000
#define P 1
struct Point{
     int x;
    int y;
};
//void mulMatri(int A[M][P],int B[P][N],int C[M][N],int m,int n,int p);
inline void mulMatri(Point** A,Point** B,float** C,int m,int n,int p);
int main()
{
    int i,j;
    Point** A,**B;
    float **C;
    A=(Point**)malloc(M*sizeof(Point *));
    B=(Point**)malloc(P*sizeof(Point *));
    C=(float**)malloc(M*sizeof(float *));
    for(i=0;i<M;i++)
        A[i]=(Point*)malloc(P*sizeof(Point));
    for(i=0;i<P;i++)
        B[i]=(Point*)malloc(N*sizeof(Point));
    for(i=0;i<M;i++)
        C[i]=(float*)malloc(N*sizeof(float));
    //int A[M][P],B[P][N],C[M][N];
    for(i=0;i<M;i++)
       for(j=0;j<P;j++)
       {
           A[i][j].x=rand()%10;
           A[i][j].y=rand()%10;
       }
    for(i=0;i<P;i++)
       for(j=0;j<N;j++)
       {
           B[i][j].x=rand()%10;
           B[i][j].y=rand()%10;
       }
    clock_t start,finish;
    start=clock();
    mulMatri( A,B,C,M,N,P);
    finish=clock();
    printf("%f ms\n",(float)(finish-start));
    system("pause");
    for(i=0;i<M;i++){
       for(j=0;j<P;j++)
          cout<<"("<<A[i][j].x<<","<<A[i][j].y<<") ";
       cout<<endl;
    }
    for(i=0;i<P;i++){
       for(j=0;j<N;j++)
          cout<<"("<<B[i][j].x<<","<<B[i][j].y<<") ";
       cout<<endl;
    }
    for(i=0;i<M;i++){
       for(j=0;j<N;j++)
          cout<<C[i][j]<<" ";
       cout<<endl;
    }
    for(i=0;i<M;i++)
        free(A[i]);
    for(i=0;i<P;i++)
        free(B[i]);
    for(i=0;i<M;i++)
        free(C[i]);
    free(A);
    free(B);
    free(C);
    return 0;
}
//void mulMatri(int A[M][P],int B[P][N],int C[M][N],int m,int n,int p)
inline void mulMatri(Point** A,Point** B,float** C,int m,int n,int p)
{
   int i,j,k;
   for(i=0;i<m;i++)
   {
       float min_value,min_idx;
       min_value=10;
       for(j=0;j<n;j++)
       {
            for(k=0;k<p;k++)
            {
                int x=A[i][k].x-B[k][j].x;
                int y=A[i][k].y-B[k][j].y;
                C[i][j]=sqrt(x*x+y*y);//不要使用pow，太慢
                /*if(C[i][j]<min_value)
                {
                    min_value=C[i][j];
                    min_idx=j;
                }*/
            }
        }
        //cout<<"person="<<i<<" "<<"car="<<min_idx<<endl;
   }
}

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