串行直方图程序

串行直方图程序#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <sys/time.h>#define MAXLINE 10000001int main（）
{
double *ptd;
char *ptc;
FILE *fp;
int i = 0;
struct timeval t_read;
double readCost=0,countCost=0;
struct timeval t_start,t_end;
double readS, start, finish;
int count[10]={0};
int num=0; ptd = （double *）malloc（MAXLINE * sizeof（double））;
ptc = （char *）malloc（10 * sizeof（char））; gettimeofday（&t_read,NULL）;
readS = t_read.tv_sec*1000 + t_read.tv_usec/1000.0; if（（fp = fopen（"data.txt","r"）） == NULL）
{
printf（"Can"t open "）;
exit（1）;
}
i=0;
while（fgets（ptc, 10, fp）！= NULL && ptc[0] ！= " " && i < MAXLINE）
{
ptd[i] = atof（ptc）;
i++;
}
num = i;
free（ptc）;
if（fclose（fp）！=0）
{
fprintf（stderr,"Error closing file "）;
}
gettimeofday（&t_start,NULL）;
start = t_start.tv_sec*1000 + t_start.tv_usec/1000.0;

for（i=0; i<num; i++）
{
count[（int）ptd[i]]++;
} gettimeofday（&t_end,NULL）;
finish = t_end.tv_sec*1000 + t_end.tv_usec/1000.0; readCost = start - readS;
countCost = finish - start;
printf（" read file spend: %f ms count datas spend: %f ms ",readCost,countCost）; for（i=0;i<10;i++）
{
printf（"%d<=x<%d: %d条 ",i,i+1,count[i]）;
}
free（ptd）;
return 0;
}