三——HASH的应用

# include <iostream>
using namespace std;
main(){
    int n;
    int g[101] = {0};
    cout<<g[0]<<endl;
    while(cin>>n && n!=0){
        int grades,grade;
        for(int i = 0;i<n;i++){
            cin>>grades;
            g[grades] = g[grades] + 1;
        }
        cin>>grade;
        cout<<g[grade]<<endl;
    }
}

# include <iostream>
# include <stdio.h>
# include <stdlib.h>
using namespace std;
int f[500001]={0};
int z[500001]={0};
main(){
    int m,n;
    while(cin>>n){
        cin>>m;

        for(int i=0;i<500000;i++){
            f[i] = 0;
            z[i] = 0;
        }

        int l;
        for(int i=0;i<n;i++){
            cin>>l;
            int m1 = abs(l);
            if(l>=0){
                z[m1] = 1;
            }else{
                f[m1] = 1;
            }
        }


        int k = 0;
        for(int i = 500000;i>=0;i--){
            if(z[i]==1){
                k++;
                cout<<i;
                if(k>=m){
                   break;
                }else{
                    cout<<" ";
                }
            }


        }
        if(k<m){
            for(int i=1;i<=500000;i++){
               if(f[i]==1){
                    cout<<"-"<<i;
                    k++;
                    if(k>=m){
                      break;
                    }else{
                        cout<<" ";
                    }
               }


            }
        }
        cout<<endl;
    }
}

**注：**数组特别大的时候要定义成全局变量，因为如果定义在main方法里面使用的栈内存，会导致溢出。

标签：HASH,cout,int,cin,grades,m1,应用,include
来源： https://blog.csdn.net/weixin_43328054/article/details/118103807