Question

为什么这段代码在代码块中不起作用...我可以在文本中输入但是我无法打印所需的直方图？代码的目的是打印直方图。这是C编程语言中的练习1-13

#include <stdio.h>

#define MAXHIST 15
#define MAXWORD 11
#define IN      1
#define OUT     0

main()
{
    int c, i, nc, state;
    int len;
    int maxvalue;
    int ovflow;
    int wl[MAXWORD];

    state = OUT;
    nc = 0;
    ovflow = 0;
    for(i=0; i < MAXWORD; ++i)
        wl[i] = 0;
    while(( c = getchar()) !=EOF) {
        if (c==' '|| c=='\n'|| c == '\t' ){
            state = OUT;
            if (nc>0)
                if (nc < MAXWORD)
                    ++wl[nc];
                else
                    ++ovflow;

            nc=0;
        }else if (state == OUT){
            state = IN;
            nc = 1;
        }else
            ++nc;
    }
    maxvalue = 0;
    for (i = 1; 1<MAXWORD; ++i)
        if (wl[i] > maxvalue)
            maxvalue = wl[i];

    for (i=1; i<MAXWORD; ++i){
        printf("%5d - %5d : ", i, wl[i]);
        if (wl[i]> 0){
            if ((len=wl[i] * MAXHIST / maxvalue) <=0)
                len = 1;
        }else
            len = 0;
        while (len > 0 ) {
            putchar('*');
            --len;
        }
        putchar('\n');
    }
    if (ovflow > 0)
            printf("There are %d words >= %d\n", ovflow, MAXWORD);
}

Answer 1

这一行是个大问题：

mp = function(k,v){
machine_id=v$machine_id
keyval(machine_id,1) }
rd = function(k,v) keyval(k,length(v))
mapreduce(input = mapreduce(input='\user\cloudera\sample.json', input.format="json" , map=function(k,v) keyval(k,v)) , map=mp, reduce = rd)

您有一个拼写错误，您可以将for (i = 1; 1<MAXWORD; ++i)与1进行比较。这条线应该是这样的：

MAXWORD

也不确定为什么在进入循环之前递增for (i = 1; i<MAXWORD; ++i)而不是之后。

练习1-13：为什么此代码在代码块中不起作用？

1 个答案: