matrix.c

它建立在最优原则的基础上,采用动态规划方法,可以优雅而高效地解决许多用贪心技术或分治技术无法解决的问题。因此,动态规划技术越来越成为解决许多重要的应用问题的关键技术。矩阵连乘。

/**
 * File    : Matrix.c
 * Author  : Wind
 * Email   : [e-mail]
 * Date    : 2005-9-30
 * Purpose : 
 * */
 
#include <stdlib.h>
#include <stdio.h>

#include "../head/Global.h"
#include "../head/Matrix.h"

 /**
  * @describ Initial Matrix
  * @return Status indicating whether matrix initializtion is successful.
  *         If success return SUCCESS,otherwise return FAIL
  * */
Status initialMatrix(Matrix * m,int row,int col){
    if(!m){
        MessageLine("Error:Encounter NULL Matrix at -- initMatrix(Matrix * m,int row,int col).");
        return FAIL;
    }
    m->row=row;
    m->col=col;
    m->array=(double*) malloc (sizeof(double) * row * col);
    if(!m->array){
        return FAIL;
    }
    return SUCCESS;
}

double * M(Matrix * m ,int row ,int col){
    if(m&&m->array){
        return &(m->array[row*m->col + col]);
    }else{
        MessageLine("Error:Encounter NULL Matrix or NULL Matrix array at -- M(Matrix * m,int row,int col).");
        return NULL;
    }
}

void printMatrix(Matrix * m){
    int i=0;
    int j=0;
    for (i = 0; i < m->row; ++i) {
        for (j = 0; j < m->col; ++j) {
            printf("%6.3lf ",*M(m,i,j));
        }
        printf("\n");
    }
}

/**
 * @describ destroy the matrix->array
 * @param   Matrix * m
 * @return  STATUS
 * */
Status destroyMatrix(Matrix * m){
    if(!m){
        return FAIL;
    }
    free(m->array);
    m->array=NULL;
    m->row=0;    
    m->col=0;    
    return SUCCESS;
}

/**
 * @describ Matrix multiply
 * @param   Matrix * a
 * @param   Matrix * b
 * @param   Matrix * c
 * @return  STATUS
 * */

Status matrixMultiply(Matrix * a,Matrix * b ,Matrix * c){
    if(!a||!b||!c){
        MessageLine("Error encountered at -- matrixMultiply (Matrix * a,Matrix * b ,Matrix * c).");
        MessageLine("Error = !a||!b||!c");
    }
    if(a->col != b->row){
        MessageLine("Error encountered at -- matrixMultiply (Matrix * a,Matrix * b ,Matrix * c).");
        MessageLine("Error = a->col != b->row ");
        return FAIL;
    }
    if(!initialMatrix(c,a->row,b->col)){
        MessageLine("Error encountered at -- matrixMultiply (Matrix * a,Matrix * b ,Matrix * c).");
        MessageLine("Error = can't init Matrix  *c .");
        return FAIL;
    }
    
    int i=0;
    int j=0;
    int k=0;
    
    for (i = 0; i < a->row; ++i) {
		for (j = 0; j < b->col; ++j) {
        		for ( k = 0; k < a->col; ++k) {
                    double * temp= M(c,i,j);
					*temp += *M(a,i,k) * (*M(b,k,j));
				}
		}
	}
    return SUCCESS;
}



Status matrixTranspose(Matrix * m){
    int i=0;
    int j=0;
    double temp=0.0;
    if(!m){
        return FAIL;
    }
    for(i=0;i<m->row;i++){
        for(j=i+1;j<m->col;j++){
            temp=*M(m,i,j);
            *M(m,i,j)=*M(m,j,i);
            *M(m,j,i)=temp;
        }
    }
    return SUCCESS;
}