最朴素的方法：
#include<cstdio> int main(){ int a,maxn=-1,minn=32769; scanf("%d",&a); if (a%2==0) maxn=a/2; if (a%4==0) minn=a/4; for (int t=1;t<=a/4;t++) for(int j=1;j<=a/2;j++) if(4*t+2*j==a){ if (t+j<minn) minn=t+j; if (t+j>maxn) maxn=t+j; } if (maxn==-1&&minn==32769) printf("0 0\n"); else printf("%d %d\n",minn,maxn); return 0; }