Question

我正在尝试使用ANSI C编写一个小应用程序。应用程序应该使用指针打印出char数组中每个字母的出现次数。

我的主要档案：

#include "alphaStats.h"

int main(void) {

    int ABStats[26] = { 0 };

    char *pAr = Ar;
    int *pABStats = ABStats;

    GetFrequency(pAr,pABStats);
    DisplayVHist(pABStats,ALPHABET_SIZE);

    return EXIT_SUCCESS;

}

alphaStats.h文件：

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include "alphaStats.c"

#define ALPHABET_SIZE 26

char Ar[] = {"All Gaul is divided into three parts, one of which the Belgae inhabit, the Aquitani another, those who in their own language are called Celts, in our Gauls, the third. All these differ from each other in language, customs and laws. The river Garonne separates the Gauls from the Aquitani; the Marne and the Seine separate them from the Belgae. Of all these, the Belgae are the bravest, because they are furthest from the civilization and refinement of [our] Province, and merchants least frequently resort to them, and import those things which tend to effeminate the mind; and they are the nearest to the Germans, who dwell beyond the Rhine , with whom they are continually waging war; for which reason the Helvetii also surpass the rest of the Gauls in valor, as they contend with the Germans in almost daily battles, when they either repel them from their own territories, or themselves wage war on their frontiers. One part of these, which it has been said that the Gauls occupy, takes its beginning at the river Rhone ; it is bounded by the river Garonne, the ocean, and the territories of the Belgae; it borders, too, on the side of the Sequani and the Helvetii, upon the river Rhine , and stretches toward the north. From 'Caesar's Conquest of Gaul', Translator. W. A. McDevitte. Translator. W. S. Bohn. 1st Edition. New York. Harper & Brothers. 1869. Harper's New Classical Library. Published under creative commons and available at http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.02.0001"};

int GetFrequency(char*,int*);
void DisplayVHist(int*,int);

alphaStats.c文件：

int GetFrequency(char *pAr, int *pABStats) {
    for (; pAr != '\0'; pAr++) {
        char c = *pAr;
        if (!isalpha(c)) continue;

        pABStats[(int)(toupper(c) - 'A')]++;
    }
    return 0;
}

void DisplayVHist(int *pABStats, int size) {
    int i;
    for (i = 0; i < size; i++) {
        printf("'%c' has %2d occurrences.\n", i + 'a', *pABStats++);
    }
}

我需要使用指针来确定Ar []中出现的每个字符的出现次数（即使用pAr和pABStats）。运行上面的代码时出现分段错误。

有人知道为什么我的代码无法运行，并且可能帮我完成编码吗？感谢。

Answer 1

您错过了*。

for (; pAr != '\0'; pAr++) {
//    ^ need a *

其他评论：

#include s通常应位于.c文件中，除非您需要标题中的类型或内容。此外，

#include "alphaStats.c"

永远不要包含.c文件。一次编译所有内容（gcc foo.c bar.c -o program）或（更频繁地）使用目标文件（gcc -c foo.c; gcc -c bar.c; gcc foo.o bar.o -o program）。所有这些gcc都应该启用警告（-Wall -Wextra -pedantic），在示例中省略它们就更清楚了。

接下来，

char Ar[] = {"..."};

不确定为什么要编译，但你应该放弃括号。字符串已经是char[] 此外，它应该在其中一个C文件中，如果您需要在另一个文件中放置extern char Ar[]。

最后，值得花时间弄清楚如何使用gdb。

如何使用C显示数组中每个字母字符的出现次数？

1 个答案: