逆序数问题C++多种方法实现

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <vector>
using namespace std;
int main(){

    //day:5/29
    //question:逆序数问题
    //input:   9 2 7 4 -1 
    //output:(9,2),(9,7),(9,4),(9,-1),(2,-1),(7,4),(7,-1),(4,-1)

    //方法一：暴力枚举法
    vector<int> v={9,2,7,4,-1};
    int ans=0;
    for(int i=0;i<v.size();i++){
        for(int j=i+1;j<v.size();j++){
            if(v[i]>v[j]){
                ans++;
                cout<<"("<<v[i]<<","<<v[j]<<")"<<endl;
            }
        }
    }
    cout<<ans;
    system("pause");
    return 0;
}

标签：多种,枚举法,int,namespace,C++,ans,include,序数
来源： https://blog.csdn.net/qq_44833392/article/details/117386371