百花2022年 计算机类数据结构作业5

A

字符串变换

 

#include<bits/stdc++.h>
using namespace std;
int main()
{
    string a,b;
    int n,m,k=0;
    cin>>n>>m;
    cin>>a>>b;
    for(int i=0;i<min(m,n);i++){
        if(a[i]!=b[i]) k++;
    }
    cout<<k+abs(m-n);
    return 0;
}

B	字符串求反

 

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n;
    string s;
    cin>>s;
    reverse(s.begin(),s.end());
    cout<<s.length()<<endl;
    cout<<s;
    return 0;
}

D	字符串匹配（朴素算法）-附加代码模式

#include<bits/stdc++.h>
using namespace std;
#define max 20000000
int findPos(char s[],char t[]){
    int m=strlen(s),n=strlen(t);
    int i=0,j=0;
    while(i<m&&j<n){
        if(s[i]==t[j]){
            i++,j++;
        }
        else{
            i=i-j+1;
            j=0;
        }
    }
    if(j>=n) return i-j;
    else return -1;
}

 

E	求解最长首尾公共子串-附加代码模式

 

#include<bits/stdc++.h>
using namespace std;
#define max 100
int nex[max+7];
int calcLCT(char t[]){
    if(strlen(t)==1) return -1;
    nex[0]=-1,nex[1]=0;
    for(int i=1,j=-1;i<strlen(t);i++){
        while(j!=-1&&t[i]!=t[j+1]) j=nex[j];
        if(t[i]==t[j+1]) j++;
        nex[i]=j;
    }
    int len=-1;
    for(int i=0;i<strlen(t);i++) 
        if(len<nex[i]) len=nex[i];
    return len+1;     
}

F	算法4-7：KMP算法中的模式串移动数组-附加代码模式

#include<bits/stdc++.h>
using namespace std;
#define max 100
//int nex[max+7];
void getNext(char t[],int nex[]){
    //if(strlen(t)==1) return -1;
    nex[0]=-1,nex[1]=0;
    for(int i=2;i<strlen(t);i++){
        int k=nex[i-1];
        while(k>=0&&t[k]!=t[i-1]) k=nex[k];
        //if(t[i]==t[j+1]) j++;
        nex[i]=k+1;
    }
    //int len=-1;
    //for(int i=0;i<strlen(t);i++) 
    //    if(len<nex[i]) len=nex[i];
    //return len+1;     
}
/*int main()
{
    char t[max];
    cin>>t;
    int len=strlen(t);
    int next[len];
    getNext(t,next);
    for(int i=0;i<len;i++) cout<<next[i]<<" ";
    return 0;
}*/

 

G	数据结构作业03 -- 改进的nextVal向量

 

#include<bits/stdc++.h>
using namespace std;
#define max 300
//int nex[max+7];
void getNext(char t[],int nex[]){
    //if(strlen(t)==1) return -1;
    nex[0]=-1,nex[1]=0;
    int i=0,j=-1;
    while(i<strlen(t)){
        if(j==-1||t[i]==t[j]){ 
            i++,j++;
            if(t[i]!=t[j]) nex[i]=j;
            else nex[i]=nex[j];
        }
        else j=nex[j];
    }
 
    //int len=-1;
    //for(int i=0;i<strlen(t);i++) 
    //    if(len<nex[i]) len=nex[i];
    //return len+1;     
}
int main()
{
    char t[max];
    while(cin>>t){
        int len=strlen(t);
        int next[len];
        getNext(t,next);
        for(int i=0;i<len;i++) cout<<next[i]<<" ";
        cout<<endl;
    }
    
    return 0;
}

H	算法4-6：字符串匹配算法执行次数比较（朴素、KMP、改进的KMP）-附加代码模式

 

#include<bits/stdc++.h>
using namespace std;
#define max 300
int findPos(char s[], char t[]){
    int count=0;
    int m=strlen(s), n= strlen(t);
    int i=0,j=0;
    while(i<m && j<n){
        count++;
        if(s[i]==t[j]) i++,j++;
        else{
            i=i-j+1;
            j=0;
        }
    }
    cout<<"count in findPos is:"<<count<<endl;
    if(j>=n) return i-j;
    else return -1;
}
// calculate the next array for KMP algorithm
void CalcNext(char t[],int nex[]){
    nex[0]=-1,nex[1]=0;
    for(int i=2;i<=strlen(t);i++){
        int k=nex[i-1];
        while(k>=0&&t[k]!=t[i-1]) k=nex[k];
        nex[i]=k+1;
    }
}
// calculate the nextVal array for improved KMP algorithm
void CalcNextVal(char t[],int nex[],int nextVal[]){
    /* write your code */
    nextVal[0]=-1,nextVal[1]=0;
    int i=0,j=-1;
    while(i<strlen(t)){
        if(j==-1||t[i]==t[j]){
            i++,j++;
            if(t[i]!=t[j]) nextVal[i]=j;
            else nextVal[i]=nextVal[j];
        }
        else j=nextVal[j];
    }
}
// using KMP algorithm to find the position of T in S
int findPos_kmp(char s[], char t[], int nex[]){
     int count=0;
     int m = strlen(s), n = strlen(t);
     int i=0,j=0;
     while(i<m && j<n){
         count++;
         if(j==-1||s[i]==t[j]){
             i++,j++;
         }
         else{
             j=nex[j];
         }
      }
      cout<<"count in findPos_kmp is:"<<count<<endl;
      if(j>=n) return i-n;
      else return -1;
    }
 
/*int main(){
     // char S[]="ababcabcac",T[]="abcac",T2[]=" ababc";
    // char S[]="aaabaaabaaabaaabaaabaaabaaabaaabaaabaaabaaabaaaaaaaab",T[]="aaaaaaaaab",T2[]=" aaaab";
    // freopen("1.txt","r",stdin);
    char S[max], T[max];
    while(cin >> S >> T){
        cout<<S<<endl;
        cout<<T<<endl;
        cout<<"the length of S and T is " << strlen(S) << " and " << strlen(T) << endl;
 
        int pos = findPos(S,T);
        cout<<"findPos:"<<pos<<endl;
        cout<<endl;
 
        int next[strlen(T)];
        CalcNext(T,next);
        cout<<"next array is:";
        for(int i=0;i<strlen(T);i++){
            cout<<next[i]<<" ";
        }
        cout<<endl;
        cout<<endl;
 
        pos=findPos_kmp(S,T,next);
        cout<<"findPos_kmp:"<<pos<<endl;
        cout<<endl;
 
        int nextVal[strlen(T)+1];
        CalcNextVal(T,next,nextVal);
        cout<<"nextVal array is:";
        for(int i=1;i<strlen(T);i++){
              cout<<nextVal[i]<<" ";
         }
         cout<<endl;
         cout<<endl;
 
         pos=findPos_kmp(S,T,nextVal);
         cout<<"findPos_improved_kmp:"<<pos<<endl;
         cout<<endl;
     }
 
      return 0;
}*/