8、串的顺序存储

1、代码实现

#include<stdio.h>
#include<malloc.h>
#include<assert.h>
#include<string.h>
//"abcdef" => "abcdef/0
// 用数组第一个空间存储字符串长度  5 a b c e f  
#define MAX_STR_LEN 20
#define u_char unsigned char

//串结构顺序存储定义 
typedef u_char StackString[MAX_STR_LEN + 1];//多一个存储'\0'

//初始化 
void initString(StackString S){
    S[0] = '\0';
}

//赋值 
void strAssign(StackString S,char *str){
    int len = strlen(str);
    int i = 0;
    for(i;i < len;i++){
        S[i] = str[i];
    }
    S[len] = '\0';
}

//拷贝
void strCopy(StackString S,StackString T){
    int len = strlength(T);
    int i = 0;
    for(i;i < len;i++){
        S[i] = T[i];
    }
    S[len] = '\0';
}

//长度
int strlength(StackString S) {
    int len = 0;
    while(*S != '\0'){
        len++;
        S++;
    }
    return len;
}

//判空
int StrEmpty(StackString S) {
    return S[0] == '\0';
}

//比较[S > T => 1 ; S == T => 0 ; S < T => -1] 
int StrCompare(StackString S,StackString T){
    int result = 0;
    while(*S != '\0' || *T != '\0'){
        result = *S - *T;
        if(result != 0)
            break;
        S++;
        T++;
    }
    
    if(result > 0)
        result = 1;
     else if(result < 0)
        result = -1;
        
    return result;
}

//连接 串s1 和 串s2 并赋值给 Y
void StrConcat(StackString Y,StackString s1,StackString s2) {
    int len1 = strlength(s1);
    int len2 = strlength(s2);
    
    if(len1 + len2 <= MAX_STR_LEN){
        //如果两个串长度相加不超过最大长度 
        //两个都可以拷贝进去 
        int i = 0;
        int j = 0;
        for(i;i < len1;i++){
            Y[i] = s1[i];
        } 
        for(j;j < len2;j++){
            Y[i + j] = s2[j];
        }
        Y[len1 + len2] = '\0';
    }else if(len1 < MAX_STR_LEN){
        //s1都拷贝,s2部分拷贝
        int i = 0;
        int j = 0;
        for(i;i < len1;i++){
            Y[i] = s1[i];
        }
        for(j;j < MAX_STR_LEN - len1;j++){
            Y[i + j] = s2[j];
        }
        Y[MAX_STR_LEN] = '\0';
    } else{
        //只能拷贝s1
        int i = 0; 
        for(i;i < MAX_STR_LEN;i++){
            Y[i] = s1[i];
        }
        Y[MAX_STR_LEN] = '\0'; 
    }
} 

//从S的 pos开始剪切len长度 的子串给sub 
void SubString(StackString S,StackString sub,int pos,int len){
    int s_len = strlength(sub);
    if(pos < 0 || pos >= len || len < 0 || len > s_len)
        return;
    int i = 0;
    for(i;i < len;i++){
        sub[i] = S[pos + i];
    }
    sub[len] = '\0';
}

void StrInsert(StackString S,int pos,StackString T){
    int s_len = strlength(S);
    int t_len = strlength(T);
    
    if(s_len + t_len <= MAX_STR_LEN){
        int i = s_len - 1;
        //先把S的pos位置之后的元素挪动到后面 
        for(i;i >= pos;i--){
            S[i + t_len] = S[i];
        } 
        int j = pos;
        for(i = 0;i < t_len;i++){
            S[j + i] = T[i];
        }
        S[s_len + t_len] = '\0';
    } else if(s_len < MAX_STR_LEN){
        //只能拷贝T的部分
        int i = s_len - 1;
        //先把S的pos位置之后的元素挪动到后面 
        for(i;i >= pos;i--){
            S[i + t_len] = S[i];
        } 
        //不能完全拷贝T 只能拷贝T的部分
        t_len =  MAX_STR_LEN - s_len;
        int j = pos;
        for(i = 0;i < t_len;i++){
            S[j + i] = T[i];
        }
        S[s_len + t_len] = '\0';
    }
}

//在S串pos位置删除len长度字符
void strDelete(StackString S,int pos,int len) {
    int s_len = strlength(S); 
    int i = pos;
    for(i;i < s_len;i++){
        S[i] = S[i + len];
    }
    S[s_len - len] = '\0';
}

void strClear(StackString S){
    S[0] = '\0';
}
void printString(StackString S){
    printf("%s\n",S);
}

//模式匹配[注意：计算机中存储的是0 1,模式匹配算法在计算机中很有用]
int strIndex(StackString S,StackString T,int pos){
    int i = pos;
    int j = 0;
    while(S[i] != '\0' && T[j] != '\0'){
        if(S[i] == T[j]){
            i++;
            j++;
        } else {
            //i回到开始下标的下一个 
            i = i - j + 1;
            j = 0;
        }
    } 
    if(T[j] == '\0')
        return i - j;
    return -1;
}  

//把主串S中的 子串T 全部换成 子串V 
void strReplace(StackString S,StackString T,StackString V){
    int s_len = strlength(S);
    int t_len = strlength(T);
    int v_len = strlength(V);
    
    int index = -1;
    int pos = 0;
    while(pos < s_len){
        index = strIndex(S,T,pos);
        if(index == -1){
            return;
        }
        //先删除 
        strDelete(S,index,t_len);
        //在插入
        StrInsert(S,index,V);
        //更改下一次匹配的位置为 上一次匹配的位置 + 字串V的长度 
        pos = index + v_len;
    }

}
int main(){
    StackString S;// =>unsigned char[MAX_STR_LEN + 1]
    strAssign(S,"abqwqcdefqwqss");
    printString(S);
    
//    StackString sub;
//    strAssign(sub,"123");
//    StrInsert(S,2,sub);
//    printString(sub);

//    StackString T;
//    strAssign(T,"adaaa");
//    int i = strIndex(S,T,0);
//    printf("%d",i);
    
    StackString T;
    initString(T);
    strAssign(T,"qwq");
    
    StackString V;
    initString(V);
    strAssign(V,"ovo");
    strReplace(S,T,V);
    printString(S);

    return 0;
}