#include
     
      int main(){    int c, q = 1;    while ((c = getchar()) != EOF) {//用getchar（）可以边读取边处理        if (c == '"') {            printf("%s", q ? "“" : "”");            q = !q;        }        else            printf("%c", c);    }    return 0;}
     

#include "stdafx.h"#include
     
      char s[] = "`1234567890-=qwertyuiop[]\asdfghjkl;'zxcvbnm,./";//注意“\\”给\转义int main(){    char c;    int i;    while ((c = getchar()) != EOF) {        for (i = 1; s[i] && s[i] != c; i++);        if (s[i])            putchar(s[i - 1]);        else putchar(c);    }}
     

 

测试

#include
     
      char s[] = "abc";int i[] = { 1,2,3 };int main(){    printf("%d\n", i[3]);    printf("%d\n", s[3]);    printf("%c\n", s[3]);    if (s[2]) printf("%s", "success");    if (s[3])printf("%s", "faile");}