第十周--编程题在线测试

1数字字符串转换为整型数

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

#define N 8

int Transform(char str[]);

int main(void)
{
    char str1[N+1];
    printf("Input a string:");
    gets(str1);
    printf("%d\n", Transform(str1));
    return 0;
}

int  Transform(char str[])
{
    char a[8];
    int counter=0;
    for (int i = 0; *(str + i) != '\0'; i++)
    {
        if (*(str + i) <= 57 && *(str + i) >= 48)
        {
            *(a + counter) = *(str + i);
            counter++;
        }
    }
    *(a + counter) = '\0';
    return atoi(a);

}

2查找子串

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

int SearchString(char str[], char astr[]);

int main(void)
{
    char str[80];
    char astr[80];
    int Position;
    printf("Input a string:");
    gets(str);
    printf("Input another string:");
    gets(astr);
    Position = SearchString(str, astr);
    if (Position == -1)
        printf("Not found!\n");
    else
        printf("Searching results:%d\n", Position);
    return 0;
}

int SearchString(char str[], char astr[])
{
    char a[80];
    int i = 0;
    int m,n;
    int counter = 0;
    int lenas = strlen(astr);
    for (i = 0; *(str + i) != '\0'; i++)
    {
        if (*(str + i) == *astr)
        {
            for (m = 0, n = i; m < lenas; m++, n++)
                if (*(str + n) == *(astr + m))
                    counter++;
            if (counter == lenas)
                return i + 1;
            else
                counter = 0;
        }
    }
    return -1;
}

3统计重复字符

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

char CountRepeatSrr(char str[], int *counter);

int main(void)
{
    char str[80];
    int max;
    char tag;
    printf("Input a string:\n");
    gets(str);
    tag = CountRepeatSrr(str, &max);
    printf("%c:%d", tag, max);
    return 0;
}

char CountRepeatSrr(char str[], int* max)
{
    char tag = *str;
    *max = 1;
    int counter =1;
    for (int i = 0; *(str + i) != 0; i++)
    {
        if (*(str + i) == *(str + i + 1))
        {
            counter++;
            if (counter > *max)
            {
                *max = counter;
                tag = *(str + i);
            }
        }
        else
            counter = 1;
    }
    return tag;
}

4凯撒密码

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

void Caesar(char str[]);

int main(void)
{
    char str[100];
    printf("Input a string:");
    gets(str);
    Caesar(str);
    return 0;
}


void Caesar(char str[])
{
    int i;
    for (i = 0; *(str + i) != 0; i++)
    {
        if (*(str + i) < 'x')
            *(str + i) += 3;
        else
            *(str + i) -= 23;
    }
    *(str + i) = 0;
    puts(str);
}