c++ 刷题代码加速

原创已于 2024-06-11 12:01:48 修改 · 478 阅读

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#c++ #开发语言

于 2024-05-05 14:48:27 首次发布

文章介绍了C++代码中的预处理器指令用于优化编译设置（如无栈保护、SSE等），以及如何同步I/O流以提高程序性能。还展示了一个名为Solution的类，包含计算子数组平均值的方法。

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代码

#define __SANITIZE_ADDRESS__ 0
#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast,no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("unroll-loops")

auto _ = []() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    return nullptr;
}();

代码二

namespace fast_IO{
#define FASTIO
#define IOSIZE 1000000
    char ibuf[IOSIZE],obuf[IOSIZE];char*p1=ibuf,*p2=ibuf,*p3=obuf;
#ifdef ONLINE_JUDGE
    #define getchar()((p1==p2)and(p2=(p1=ibuf)+fread(ibuf,1,IOSIZE,stdin),p1==p2)?(EOF):(*p1++))
    #define putchar(x)((p3==obuf+IOSIZE)&&(fwrite(obuf,p3-obuf,1,stdout),p3=obuf),*p3++=x)
#endif
#define isdigit(ch)(ch>47&&ch<58)
#define isspace(ch)(ch<33)
    template<typename T>inline T read(){T s=0;int w=1;char ch;while(ch=getchar(),!isdigit(ch)and(ch!=EOF))if(ch=='-')w=-1;if(ch==EOF)return false;while(isdigit(ch))s=s*10+ch-48,ch=getchar();return s*w;}template<typename T>inline bool read(T&s){s=0;int w=1;char ch;while(ch=getchar(),!isdigit(ch)and(ch!=EOF))if(ch=='-')w=-1;if(ch==EOF)return false;while(isdigit(ch))s=s*10+ch-48,ch=getchar();return s*=w,true;}inline bool read(char&s){while(s=getchar(),isspace(s));return true;}inline bool read(char*s){char ch;while(ch=getchar(),isspace(ch));if(ch==EOF)return false;while(!isspace(ch))*s++=ch,ch=getchar();*s='\000';return true;}template<typename T>inline void print(T x){if(x<0)putchar('-'),x=-x;if(x>9)print(x/10);putchar(x%10+48);}inline void print(char x){putchar(x);}inline void print(char*x){while(*x)putchar(*x++);}inline void print(const char*x){for(int i=0;x[i];i++)putchar(x[i]);}
#ifdef _GLIBCXX_STRING
    inline bool read(std::string&s){s="";char ch;while(ch=getchar(),isspace(ch));if(ch==EOF)return false;while(!isspace(ch))s+=ch,ch=getchar();return true;}inline void print(std::string x){for(int i=0,n=x.size();i<n;i++)putchar(x[i]);}
#endif
    template<typename T,typename...T1>inline int read(T&a,T1&...other){return read(a)+read(other...);}template<typename T,typename...T1>inline void print(T a,T1...other){print(a);print(other...);}struct Fast_IO{~Fast_IO(){fwrite(obuf,p3-obuf,1,stdout);}}io;template<typename T>Fast_IO&operator>>(Fast_IO&io,T&b){return read(b),io;}template<typename T>Fast_IO&operator<<(Fast_IO&io,T b){return print(b),io;}
}
#define cin fast_IO::io
#define cout fast_IO::io
#define endl '\n'

使用例子

#define __SANITIZE_ADDRESS__ 0
#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast,no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("unroll-loops")

auto _ = []() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    return nullptr;
}();

class Solution {
public:
    vector<int> getAverages(vector<int>& nums, int k) {
        int n = nums.size();
        vector<int> ans(n, -1);
        long long sum = 0;
        for (int i = 0; i < min(n, k << 1); i++) {
            sum += nums[i];
        }
        for (int i = k; i + k < n; i++) {
            sum += nums[i + k];
            ans[i] = sum / (2 * k + 1);
            sum -= nums[i - k];
        }
        return ans;
    }
};

int init = []
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    ofstream out("user.out");
    for (string s; getline(cin, s);)
    {
        if (s != "0")
            out << "Intersected at '" << s << "'\n";
        else
            out << "No intersection\n";
        for (int i = 0; i < 4; ++i)
            getline(cin, s);
    }
    out.flush();
    exit(0);
    return 0;
}();