第二题A了90%，贴个代码： ``` /* ...... */ auto eat = [](int a){ return a/2 + a%2; }; auto eat2 = [&;](int a,int b){ if(a>b) swap(a,b); int tmp = 2*a-b; if(tmp < 0) return eat(b); tmp *= 2; return b-a + tmp/3 + (tmp%3>0 ? 1 : 0); }; int m1,m2,ans; m1 = m2 = ans = 1000; for(int i = 0;i<n;++i){ m2 = min(m2,eat(v[i])); if(m1 > m2) swap(m1,m2); if(i >= 1){ ans = min(ans, eat2(v[i-1],v[i])); } if(i >= 2){ ans = min(ans,eat(v[i-2]-1)+eat(v[i]-1)+1); } } ans = min(ans,m1+m2); cout << ans; ```