Question

问题陈述：编写一个程序，读取一组文本行并打印最长的文本。

程序：

#include <stdio.h>
#define MAX 100

int getlinetext(char s[]);

int main(void)
{
    char longest[MAX];
    int longestlenght = 0;
    char line[MAX];
    int lenght;

    while ((lenght = getlinetext(line)) > 0){
        if(lenght > longestlenght){
            longestlenght = lenght;
            int i = 0;
            while (line[i] != '\0'){
                longest[i] = line[i];
                i++;
            }
            longest[i] = '\0';
        }
    }
    printf("The longest lenght is %d\n", longestlenght);
    printf("%s\n", longest); 
    return 0;
}

int getlinetext(char line[])
{
    int i=0;
    int c;
    while ((c = getchar()) != EOF){
        line[i] == c;
        if (c == '\n')
            break;
        i++;
    }
    line[i] = '\0';
    return i;
}

预期产出：

hello
world!!
The longest lenght is 7
world!!

实际输出：

hello
world!!
The longest lenght is 7
�

不知何故，我能够打印正确的最长长度而不是字符串本身。我以为我错过了空字节，但它就在那里，错误仍然存在。

Answer 1

正如@chux指出的那样，我在第34行使用等号（“==”）代替分配符号（“=”）犯了一个愚蠢的错误：

line[i] == c -> line[i] = c

所以纠正的程序将是

#include <stdio.h>
#define MAX 100

int getlinetext(char s[]);

int main(void)
{
    char longest[MAX];
    int longestlenght = 0;
    char line[MAX];
    int lenght;

    while ((lenght = getlinetext(line)) > 0){
        if(lenght > longestlenght){
            longestlenght = lenght;
            int i = 0;
            while (line[i] != '\0'){
                longest[i] = line[i];
                i++;
            }
            longest[i] = '\0';
        }
    }
    printf("The longest lenght is %d\n", longestlenght);
    printf("%s\n", longest); 
    return 0;
}

int getlinetext(char line[])
{
    int i=0;
    int c;
    while ((c = getchar()) != EOF){
        line[i] = c;
        if (c == '\n')
            break;
        i++;
    }
    line[i] = '\0';
    return i;
}

无法输出最长的字符串

1 个答案: