两种矩阵转置的代码

#include<stdio.h>
#include<stdlib.h>

//#define MAX_TERMS 101
#define MAX_COL 50

typedef struct
{
	int row;
	int col;
	int value;
}term;

//term a[MAX_TERMS];

/*void transpose(term a[], term b[])
{
	int n,i,j,currentb;
	n=a[0].value;
	b[0].row=a[0].col;
	b[0].col=a[0].row;
	b[0].value=n;

	if(n>0)
	{
		currentb=1;
		for(i=0;i<a[0].col;i++)
			for(j=1;j<=n;j++)
				if(a[j].col==i)
				{
					b[currentb].row=a[j].col;
					b[currentb].col=a[j].row;
					b[currentb].value=a[j].value;
					currentb++;
				}
	}
}*/

void fast_transpose(term a[], term b[])
{
	
	int row_terms[MAX_COL],starting_pos[MAX_COL];
	int i,j,num_cols=a[0].col,num_terms=a[0].value;
	b[0].row=num_cols;
	b[0].col=a[0].row;
	b[0].value=num_terms;

	if(num_terms>0)
	{
		for(i=0;i<num_cols;i++)
			row_terms[i]=0;
		for(i=1;i<=num_terms;i++)
			row_terms[a[i].col]++;
		starting_pos[0]=1;
		for(i=1;i<num_cols;i++)
			starting_pos[i]=starting_pos[i-1]+row_terms[i-1];
		for(i=1;i<=num_terms;i++)
		{
			j=starting_pos[a[i].col]++;
			b[j].row=a[i].col;
			b[j].col=a[i].row;
			b[j].value=a[i].value;
		}
	}
}

int main(int argc, char **argv)
{
	int i;
	term a[9]={{6,6,8},{0,0,15},{0,3,22},{0,5,-15},{1,1,11},{1,2,3},{2,3,-6},{4,0,91},{5,2,28}};
	term b[9];

//	transpose(a,b);
        fast_transpose(a,b);
        
	for(i=0;i!=9;++i)
		printf("%5d %5d %5d 
",b[i].row,b[i].col,b[i].value);
	printf("
");
}