HDU6168 Numbers

Posted 2020-10-03 2855669158

题意：一个序列由原序列的任意两个数相加得到，给出新序列，求原序列

题解：找到最小的两个值就是原序列的最小的两个，删掉两个数的和，重复上面步骤

#include <bits/stdc++.h>
#define ll long long
#define maxn 130100
using namespace std;
map<int,int>mp;
int a[maxn], ans[maxn];
inline void gg(int x){
    if(mp[x] == 1) mp.erase(x);
    else mp[x]--;
}
int main(){
    int n, num, t;
    while(~scanf("%d", &n)){
        num = 0; mp.clear();
        for(int i=0;i<n;i++) scanf("%d", &t), mp[t]++;
        ans[num++] = mp.begin()->first;
        gg(ans[num-1]);
        ans[num++] = mp.begin()->first;
        gg(ans[num-1]);
        while(1){
            for(int i=0;i<num-1;i++)
                gg(ans[i]+ans[num-1]);
            if(mp.size() == 0) break;
            ans[num++] = mp.begin()->first;
            gg(ans[num-1]);
        }
        cout<<num<<endl;
        for(int i=0;i<num;i++)
            printf("%d%c", ans[i], i==num-1?‘\n‘:‘ ‘);
    }
    return 0;
}