Make Them Similar

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mb5ffd6fed5661e 2021-08-19 11:13:00

文章标签 题解 #include i++ ios 折半 文章分类 后端开发

感想：奇奇怪怪的STL和奇奇怪怪的折半

#include<iostream>
#include<cstdio>
#include<cmath>
#include<map>
#include<queue>
#include<algorithm>
#include<cstring>
#include<string>
using namespace std;
map<vector<int>,int> m;
int a[100001]={0};
int Min(int X,int Y){
    return X<Y ? X : Y;
}
int Max(int X,int Y){
    return X>Y ? X : Y;
}
inline int read(){
    int s=0,w=1;
    char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
    while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
    return s*w;
}
int pop_count(int shu){
    int ans=0;
    while(shu!=0){
        if(shu%2==1) ans++;
        shu/=2;
    }
    return ans;
}
int main(){
    int n;
    ios::sync_with_stdio(false);
    n=read();
    for(int i=1;i<=n;i++) a[i]=read();
    //前15位
    for(int i=0;i<(1<<15);i++){
        vector<int> v;
        int bz=pop_count((a[1]>>15)^i);
        for(int j=2;j<=n;j++) v.push_back(bz-pop_count((a[j]>>15)^i));
        m[v]=i;
    } 
    //后15位
    for(int i=0;i<(1<<15);i++){
        vector<int> v;
        int bz=pop_count(((a[1]-((a[1]>>15)<<15)))^i);
        for(int j=2;j<=n;j++) v.push_back(pop_count(((a[j]-((a[j]>>15)<<15)))^i)-bz);
        if(m[v]!=0){
            printf("%d",(m[v]<<15)+i);
            return 0;
        }
    } 
    printf("-1");
    return 0;
}