A
按位枚举。
#include<iostream> #include<cstring> #include<cstdio> #include<cstring> #include<vector> #include<queue> #include<algorithm> #define pii pair<int,int> #define pb push_back #define mp make_pair #define fi first #define se second using namespace std; inline int read(){ int f=1,ans=0;char c=getchar(); while(c<'0'||c>'9'){if(c=='-')f=-1;c=getchar();} while(c>='0'&&c<='9'){ans=ans*10+c-'0';c=getchar();} return f*ans; } int T,A,B; int main(){ T=read(); while(T--){ A=read(),B=read();int Ans=0; for(int i=30;i>=0;i--){ bool a=A&(1<<i),b=B&(1<<i); int cnt=a+b; if(cnt==2||cnt==0) continue; Ans+=(1<<i); }printf("%d\n",Ans); }return 0; }