引号替换 前位输出

#include<stdio.h>
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<stdio.h>
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<stdio.h>
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");
}