题解 | 单词替换

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

int main() {
    char s[1010];
    while (fgets(s, 1010, stdin) != NULL) {
        int n = strlen(s);
        if (n > 0 && s[n - 1] == '\n') {
            s[n - 1] = '\0';
        }
        char a[101]="", b[101]="";
        if (fgets(a, 101, stdin) != NULL) {
            int an = strlen(a);
            if (an > 0 && a[an - 1] == '\n') {
                a[an - 1] = '\0';
            }
        }
        if (fgets(b, 101, stdin) != NULL) {
            int bn = strlen(b);
            if (bn > 0 && b[bn - 1] == '\n') {
                b[bn - 1] = '\0';
            }
        }
        char* token;
        char str[1000] = ""; //拼接到str字符串中
        token = strtok(s, " \n"); //根据空格截取单词
        while (token != NULL) {
            if (strcmp(a, token) == 0) {
                strcat(str, b);
            } else {
                strcat(str, token);
            }
            strcat(str, " ");
            token = strtok(NULL, " \n");
        }
        int len = strlen(str);
        if (len > 0 && str[len - 1] == ' ') {
            str[len - 1] = '\0';
        }
        printf("%s", str);
    }
    return 0;
}