分类 模板 下的文章

typedef long long ll;
const int MAXN=1e5+5;
const ll MOD=1000000007;
long long  fac[MAXN], inv[MAXN];
inline long long C(long long a, long long b) {
    return fac[a] * inv[b] % MOD * inv[a - b] % MOD;
};

inline void init(){
    inv[0] = inv[1] = fac[0] = 1;
    for (int i = 2; i < MAXN; i++) {
        inv[i] = inv[MOD%i] * (MOD - MOD / i) % MOD;//递推求逆元
    }
    for (int i = 1; i < MAXN; i++) {
        fac[i] = fac[i - 1] * i%MOD;
        inv[i] = inv[i - 1] * inv[i] % MOD;//阶乘逆元
    }
}

最长上升子序列(严格递增)

int dp[MAXN];
int LIS(vector<int>&a){
    memset(dp, 0x3f, sizeof(int)*a.size());
    int len = 1;
    dp[0] = a[0];
    for (int i = 1; i < a.size(); ++i)    {
        int pos = lower_bound(dp, dp + len, a[i]) - dp;
        dp[pos] = a[i];
        len = max(len, pos + 1);
    }
    return len;
}

long long quick_power(long long a, long long b, long long mod) {
    long long ans = 1;
    a %= mod;
    while (b) {
        if (b & 1)ans = ans * a % mod;
        a = a * a % mod;
        b >>= 1;
    }
    return ans;
}

cin,cout加速

ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);

注意:速度仍略低于scanf与printf
注意:能用'\n'尽可能不要使用endl

一般的读入挂

与scanf,cin互斥

const int BufferSize=1<<16;
char buffer[BufferSize],*fronthead,*fronttail;
inline char GET_CHAR(){
    if(fronthead==fronttail){
        int l=fread(buffer,1,BufferSize,stdin);
        fronttail=(fronthead=buffer)+l;
        if(fronthead==fronttail)return EOF;
    }
    return *fronthead++;
}
inline int READ(){
    int x=0,f=1;char c=GET_CHAR();
    for(;!isdigit(c);c=GET_CHAR()){
        if(c==EOF)return EOF;
        if(c=='-')f=-1;
    }
    for(;isdigit(c);c=GET_CHAR())x=(((x<<2)+x)<<1)+c-'0';
    return x*f;
}

特技读入挂

妈妈再也不用担心我读的慢

namespace IO{ 
    #define BUF_SIZE 100000 
    #define OUT_SIZE 100000 
    #define ll long long 
    //fread->read 
 
    bool IOerror=0; 
    inline char nc(){ 
        static char buf[BUF_SIZE],*p1=buf+BUF_SIZE,*pend=buf+BUF_SIZE; 
        if (p1==pend){ 
            p1=buf; pend=buf+fread(buf,1,BUF_SIZE,stdin); 
            if (pend==p1){IOerror=1;return -1;} 
            //{printf("IO error!\n");system("pause");for (;;);exit(0);} 
        } 
        return *p1++; 
    } 
    inline bool blank(char ch){return ch==' '||ch=='\n'||ch=='\r'||ch=='\t';} 
    inline void read(int &x){ 
        bool sign=0; char ch=nc(); x=0; 
        for (;blank(ch);ch=nc()); 
        if (IOerror)return; 
        if (ch=='-')sign=1,ch=nc(); 
        for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0'; 
        if (sign)x=-x; 
    } 
    inline void read(ll &x){ 
        bool sign=0; char ch=nc(); x=0; 
        for (;blank(ch);ch=nc()); 
        if (IOerror)return; 
        if (ch=='-')sign=1,ch=nc(); 
        for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0'; 
        if (sign)x=-x; 
    } 
    inline void read(double &x){ 
        bool sign=0; char ch=nc(); x=0; 
        for (;blank(ch);ch=nc()); 
        if (IOerror)return; 
        if (ch=='-')sign=1,ch=nc(); 
        for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0'; 
        if (ch=='.'){ 
            double tmp=1; ch=nc(); 
            for (;ch>='0'&&ch<='9';ch=nc())tmp/=10.0,x+=tmp*(ch-'0'); 
        } 
        if (sign)x=-x; 
    } 
    inline void read(char *s){ 
        char ch=nc(); 
        for (;blank(ch);ch=nc()); 
        if (IOerror)return; 
        for (;!blank(ch)&&!IOerror;ch=nc())*s++=ch; 
        *s=0; 
    } 
    inline void read(char &c){ 
        for (c=nc();blank(c);c=nc()); 
        if (IOerror){c=-1;return;} 
    } 
    //fwrite->write 
    struct Ostream_fwrite{ 
        char *buf,*p1,*pend; 
        Ostream_fwrite(){buf=new char[BUF_SIZE];p1=buf;pend=buf+BUF_SIZE;} 
        void out(char ch){ 
            if (p1==pend){ 
                fwrite(buf,1,BUF_SIZE,stdout);p1=buf; 
            } 
            *p1++=ch; 
        } 
        void print(int x){ 
            static char s[15],*s1;s1=s; 
            if (!x)*s1++='0';if (x<0)out('-'),x=-x; 
            while(x)*s1++=x%10+'0',x/=10; 
            while(s1--!=s)out(*s1); 
        } 
        void println(int x){ 
            static char s[15],*s1;s1=s; 
            if (!x)*s1++='0';if (x<0)out('-'),x=-x; 
            while(x)*s1++=x%10+'0',x/=10; 
            while(s1--!=s)out(*s1); out('\n'); 
        } 
        void print(ll x){ 
            static char s[25],*s1;s1=s; 
            if (!x)*s1++='0';if (x<0)out('-'),x=-x; 
            while(x)*s1++=x%10+'0',x/=10; 
            while(s1--!=s)out(*s1); 
        } 
        void println(ll x){ 
            static char s[25],*s1;s1=s; 
            if (!x)*s1++='0';if (x<0)out('-'),x=-x; 
            while(x)*s1++=x%10+'0',x/=10; 
            while(s1--!=s)out(*s1); out('\n'); 
        } 
        void print(double x,int y){ 
            static ll mul[]={1,10,100,1000,10000,100000,1000000,10000000,100000000, 
                1000000000,10000000000LL,100000000000LL,1000000000000LL,10000000000000LL, 
                100000000000000LL,1000000000000000LL,10000000000000000LL,100000000000000000LL}; 
            if (x<-1e-12)out('-'),x=-x;x*=mul[y]; 
            ll x1=(ll)floor(x); if (x-floor(x)>=0.5)++x1; 
            ll x2=x1/mul[y],x3=x1-x2*mul[y]; print(x2); 
            if (y>0){out('.'); for (size_t i=1;i<y&&x3*mul[i]<mul[y];out('0'),++i); print(x3);} 
        } 
        void println(double x,int y){print(x,y);out('\n');} 
        void print(char *s){while (*s)out(*s++);} 
        void println(char *s){while (*s)out(*s++);out('\n');} 
        void flush(){if (p1!=buf){fwrite(buf,1,p1-buf,stdout);p1=buf;}} 
        ~Ostream_fwrite(){flush();} 
    }Ostream; 
    inline void print(int x){Ostream.print(x);} 
    inline void println(int x){Ostream.println(x);} 
    inline void print(char x){Ostream.out(x);} 
    inline void println(char x){Ostream.out(x);Ostream.out('\n');} 
    inline void print(ll x){Ostream.print(x);} 
    inline void println(ll x){Ostream.println(x);} 
    inline void print(double x,int y){Ostream.print(x,y);} 
    inline void println(double x,int y){Ostream.println(x,y);} 
    inline void print(char *s){Ostream.print(s);} 
    inline void println(char *s){Ostream.println(s);} 
    inline void println(){Ostream.out('\n');} 
    inline void flush(){Ostream.flush();}
    #undef ll 
    #undef OUT_SIZE 
    #undef BUF_SIZE 
};