c_cpp 合并排序

Posted 2021-05-14

#include <bits/stdc++.h>
using namespace std;

void merge(vector<int> &v, int l, int m, int r){
    int c = (m-l)+1;
    int d = r - m;
    vector<int>a(c);
    for (int i = 0; i<c; i++){
        a[i] = v[l+i];
    }
    vector<int>b(d);
    for (int i=0; i<d; i++){
        b[i] = v[m+1+i];
    }
    int x=l, i=0, j=0;
    while (i<c && j<d){
        if (a[i]<b[j]){
            v[x] = a[i];
            i++;
        }else{
            v[x] = b[j];
            j++;
        }
        x++;
    }
    while (i<c){
        v[x] = a[i];
        x++;
        i++;
    }
    while (j<d){
        v[x] = b[j];
        x++;
        j++;
    }
}

void merge_sort(vector<int> &v, int l, int r){
    if (l<r){
    int m = l + (r-l)/2;
    merge_sort(v, l, m);
    merge_sort(v, m+1, r);
    merge(v, l, m ,r);
    }
}

void print(vector<int> v){
    for (int i=0; i<v.size(); i++){
        cout<<v[i]<<" ";
    }
}

int main() {
    //freopen("ip.txt","r",stdin);
    //freopen("op.txt","w",stdout);
	int t;
	cin>>t;
	while (t--){
	    int x;
	    cin>>x;
	    vector<int>v(x);
	    for (int i=0; i<x; i++){
	        cin>>v[i];
	    }
	    merge_sort (v,0,x-1);
	    print (v);
	    cout<<endl;
	}
	return 0;
}