PAT乙级-1035 插入与归并(25)

最新推荐文章于 2024-09-28 01:00:00 发布

原创最新推荐文章于 2024-09-28 01:00:00 发布 · 266 阅读

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本文提供了一种通过PAT-1-1035题目的解决方案，对比了插入排序与归并排序两种算法在特定条件下的表现。通过对两种排序算法的逐步实现与比较，确定哪种算法能更快地达到给定序列的排序状态。

思路很简单实现两个排序然后比较即可注意，题目里的“一轮”排序在merge中是指merge的size变为原来的两倍；还有临时数组开大一点，不然最后几个会有段错误

//PAT-1-1035
#include <iostream>
#include <algorithm>
#include <string>
#include <math.h>
using namespace std;


int f_insert=0;
int f_merge=0;
int f=0;
int s1[1000]={0};
int result[1000]={0};
int temarray[1000]={0};
int comp(int s0[],int s1[],int n){
    for (int i=0; i<n; i++) {
        if (s0[i]!=s1[i]) {
            return 0;
        }
    }
    
    return 1;
}
void insertion_sort(int s[],int n){
    int temp,i,j;
    for ( i=1; i<n; i++) {
        temp=s[i];
        for ( j=i; j>0&&s[j-1]>temp; j--) {
            s[j]=s[j-1];
        }
        s[j]=temp;
        if (f_insert==1&&!comp(s, s1, n)&&f==0) {
            f=1;
            for (int i=0;i<n;  i++ ) {
                result[i]=s[i];
            }
            //return;
        }
        if( comp(s, s1, n)) {
            f_insert=1;
        }
    }
    
}
void Merge(int s[],int temarray[],int left_begin,int right_begin,int right_end){
    int left_end,num,pos;
    left_end = right_begin-1;
    pos = left_begin;
    num = right_end-left_begin+1;
    
    while (left_begin<=left_end && right_begin<=right_end) {
        if (s[left_begin]<s[right_begin]) {
            temarray[pos++]=s[left_begin++];
        }else temarray[pos++]=s[right_begin++];
    }
    while (left_begin<=left_end) {
        temarray[pos++]=s[left_begin++];
    }
    while (right_begin<=right_end) {
        temarray[pos++]=s[right_begin++];
    }
    for (int i=0; i<num; i++,right_end--) {
        s[right_end]=temarray[right_end];
    }
}
void Msort_iter(int s[],int temarray[],int left,int right,int n){
    for (int i=1; i<n; i*=2) {


    
        for (int j=0; j<n; j+=i*2) {
            
            Merge(s, temarray, j, j+i,j+2*i-1<n-1?j+2*i-1:n-1);
            
            if (comp(s, s1, n)==1) {
                f_merge=1;
                
            }
            
        }
        if (f_merge==1&&comp(s, s1, n)==0&&f==0) {
            f=1;
            for (int i=0;i<n;  i++ ) {
                result[i] = s[i];
            }
            //return;
        }
    }
}
void Msort(int s[],int temarray[],int left,int right,int n){
    int pivot;
        if (left<right) {
        
        pivot = (left+right)/2;
        Msort(s, temarray, left, pivot,n);
        Msort(s, temarray, pivot+1, right,n);
       
        Merge(s,temarray,left,pivot+1,right);
            if (1) {
                for (int i=0;i<n;  i++ ) {
                    cout<<s[i]<<" ";
                }
                cout<<endl;
            }


    }
    
}


void merge_sort(int s[],int n){
    
    //temarray = new int(n);
    //if (temarray!=nullptr) {
        Msort_iter(s,temarray,0,n-1,n);
        //delete [] temarray;
    //}else cout<<"坏了，内存不够啦！";
}
int main(){
    
    int n;
    int s0[1000]={0};
    int s2[1000]={0};
    cin>>n;
    for (int i=0; i<n; i++) {
        cin>>s0[i];
        s2[i]=s0[i];
    }
    for (int i=0; i<n; i++) {
        cin>>s1[i];
    }
    insertion_sort(s0, n);
    merge_sort(s2, n);


    if (f_insert) {
        cout<<"Insertion Sort"<<endl;
        for (int i=0;i<n-1;  i++ ) {
            cout<<result[i]<<" ";
        }
        cout<<result[n-1];
        return 0;
    }
    if (f_merge) {
        cout<<"Merge Sort"<<endl;
        for (int i=0;i<n-1;  i++ ) {
            cout<<result[i]<<" ";
        }
        cout<<result[n-1];
    }
    
    return 0;
}