TCPL——练习1.13

　　坚持每天写一两道小练习:-)

　　TCPL练习1.13: 编写一个程序，打印输入中单词长度的水平和垂直直方图。很简单，就是垂直的时候，我用了二维数组，真是浪费空间啊。当然有局限性，只能规定单词长度在什么范围内。TCAB里面通过一条数学运算，没借助二维数组来实现，我没有验证，也没有看懂那运算是怎么得出结果的。

#include <stdio.h>
#include <string.h>

#define MAXLEN    11
#define OUT        0
#define IN        1

static void WordsLenCount(int *histogram)
{
    int c;
    int wordLen = 0;
    int state = OUT;

    while ((c = getchar()) != EOF) {
        if (c == ' ' || c == '\n' || c == '\t') {
            if (wordLen != 0) {
                histogram[wordLen]++;
                wordLen = 0;
                state = OUT;
            }
        } else if (state == OUT) {
            ++wordLen;    
            state = IN;
        } else {
            ++wordLen;
        }
    }
}

static void DrawHorizontalHistogram(int *histogram)
{
    int i, j;

    printf("===== DRAWING THE HOIZONTAL HISTOGRAM ====\n");
    for (i = 1; i < MAXLEN; ++i) {
        printf("%3d ", i);
        for (j = 0; j < histogram[i]; ++j) {
            printf("*");
        }
        printf("\n");
    }
}

static void DrawVerticalHistogram(int *histogram)
{
    int i, j;
    int verHistogram[MAXLEN][MAXLEN];

    memset(verHistogram, ' ', sizeof(verHistogram));

    printf("===== DRAWING THE VERTICAL HISTOGRAM ====\n");
    for (i = 1; i < MAXLEN; ++i) {
        for (j = histogram[i]; j >= 1; --j) {
            verHistogram[j][i] = '*';
        }
    }
    for (i = MAXLEN - 1; i >= 1; --i) {
        for (j = 1; j < MAXLEN; ++j) {
            printf("%c ", verHistogram[i][j]);
        }
        printf("\n");
    }
    for (i = 1; i < MAXLEN; ++i) {
        printf("%d ", i);
    }
    printf("\n");
}

int main(void)
{
    int histogram[MAXLEN] = {0};

    WordsLenCount(histogram);
    DrawHorizontalHistogram(histogram);
    DrawVerticalHistogram(histogram);

    return 0;
}