2081 Recaman's Sequence 水题报告

 #include<iostream>#include<stdio.h>using namespace std;bool in[10000000];int d[500010];int main(){int tmp = d[0] = 0;for(int i = 1; i <= 500000; i ++){if(tmp > i && !in[tmp-i])tmp -= i;else tmp += i;in[tmp] = true;d[i] = tmp;}int n;while(cin >> n && n > -1){cout << d[n] << endl;}return 0;}