5.1 字符串 六月飞雪

5.1.1   WRTYU     　http://poj.grids.cn/practice/2538/

# include <stdio.h>

char *s = "`1234567890-=QWERTYUIOP[]\ASDFGHJKL;'ZXCVBNM,./";

int main () {

    char c;
    while ((c = getchar()) != EOF) {
        int i;
        for (i = 1; s[i] && s[i]!=c; ++i);
        if (s[i]) putchar(s[i-1]);
        else putchar(c);
    }

    return 0;
}

5.1.2   TeX括号  　 http://poj.grids.cn/practice/1488/

# include <stdio.h>

int main () {

    char c;
    bool p = true;
    while ((c = getchar()) != EOF) {
        if (c == '"') {
            printf("%s", p ? "``" : "''");
            p = !p;
        }
        else putchar(c);
    }

    return 0;
}

5.1.3   周期串 　　 http://acm.hust.edu.cn:8080/judge/problem/viewProblem.action?id=19496

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

int main ()
{

    int len, n;
    char str[100];
    scanf("%d", &n);
    while (n--)
    {
        scanf("%s", str);
        len = strlen(str);
        int i, j;
        for (i = 1; i <= len; ++i)
        {
            if (len%i == 0)
            {
                int ok = 1;
                for (j = i; j < len; ++j)
                {
                    if (str[j] != str[j%i])
                    {
                        ok = 0;
                        break;
                    }
                }
                if (ok)
                {
                    printf("%d\n", i);
                    if (n) puts("");
                    break;
                }
            }
        }
    }

    return 0;
}