sat-solver/Vec.h

/*******************************************************************************************[Vec.h]
MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
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The above copyright notice and this permission notice shall be included in all copies or
substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
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**************************************************************************************************/

#ifndef Vec_h
#define Vec_h

#include <cstdlib>
#include <cassert>
#include <new>

//=================================================================================================
// Automatically resizable arrays
//
// NOTE! Don't use this vector on datatypes that cannot be re-located in memory (with realloc)

template<class T>
class vec {
    T*  data;
    int sz;
    int cap;

    void     init(int size, const T& pad);
    void     grow(int min_cap);

    // Don't allow copying (error prone):
    vec<T>&  operator = (vec<T>& other) { assert(0); return *this; }
             vec        (vec<T>& other) { assert(0); }

    static inline int imin(int x, int y) {
        int mask = (x-y) >> (sizeof(int)*8-1);
        return (x&mask) + (y&(~mask)); }

    static inline int imax(int x, int y) {
        int mask = (y-x) >> (sizeof(int)*8-1);
        return (x&mask) + (y&(~mask)); }

public:
    // Types:
    typedef int Key;
    typedef T   Datum;

    // Constructors:
    vec(void)                   : data(NULL) , sz(0)   , cap(0)    {}
    vec(int size)               : data(NULL) , sz(0)   , cap(0)    { growTo(size); }
    vec(int size, const T& pad) : data(NULL) , sz(0)   , cap(0)    { growTo(size, pad); }
    vec(T* array, int size)     : data(array), sz(size), cap(size) { }      // (takes ownership of array -- will be deallocated with 'free()')
   ~vec(void)                                                      { clear(true); }

    // Ownership of underlying array:
    T*       release  (void)           { T* ret = data; data = NULL; sz = 0; cap = 0; return ret; }
    operator T*       (void)           { return data; }     // (unsafe but convenient)
    operator const T* (void) const     { return data; }

    // Size operations:
    int      size   (void) const       { return sz; }
    void     shrink (int nelems)       { assert(nelems <= sz); for (int i = 0; i < nelems; i++) sz--, data[sz].~T(); }
    void     shrink_(int nelems)       { assert(nelems <= sz); sz -= nelems; }
    void     pop    (void)             { sz--, data[sz].~T(); }
    void     growTo (int size);
    void     growTo (int size, const T& pad);
    void     clear  (bool dealloc = false);
    void     capacity (int size) { grow(size); }

    // Stack interface:
#if 1
    void     push  (void)              { if (sz == cap) { cap = imax(2, (cap*3+1)>>1); data = (T*)realloc(data, cap * sizeof(T)); } new (&data[sz]) T(); sz++; }
    //void     push  (const T& elem)     { if (sz == cap) { cap = imax(2, (cap*3+1)>>1); data = (T*)realloc(data, cap * sizeof(T)); } new (&data[sz]) T(elem); sz++; }
    void     push  (const T& elem)     { if (sz == cap) { cap = imax(2, (cap*3+1)>>1); data = (T*)realloc(data, cap * sizeof(T)); } data[sz++] = elem; }
    void     push_ (const T& elem)     { assert(sz < cap); data[sz++] = elem; }
#else
    void     push  (void)              { if (sz == cap) grow(sz+1); new (&data[sz]) T()    ; sz++; }
    void     push  (const T& elem)     { if (sz == cap) grow(sz+1); new (&data[sz]) T(elem); sz++; }
#endif

    const T& last  (void) const        { return data[sz-1]; }
    T&       last  (void)              { return data[sz-1]; }

    // Vector interface:
    const T& operator [] (int index) const  { return data[index]; }
    T&       operator [] (int index)        { return data[index]; }


    // Duplicatation (preferred instead):
    void copyTo(vec<T>& copy) const { copy.clear(); copy.growTo(sz); for (int i = 0; i < sz; i++) new (&copy[i]) T(data[i]); }
    void moveTo(vec<T>& dest) { dest.clear(true); dest.data = data; dest.sz = sz; dest.cap = cap; data = NULL; sz = 0; cap = 0; }
};

template<class T>
void vec<T>::grow(int min_cap) {
    if (min_cap <= cap) return;
    if (cap == 0) cap = (min_cap >= 2) ? min_cap : 2;
    else          do cap = (cap*3+1) >> 1; while (cap < min_cap);
    data = (T*)realloc(data, cap * sizeof(T)); }

template<class T>
void vec<T>::growTo(int size, const T& pad) {
    if (sz >= size) return;
    grow(size);
    for (int i = sz; i < size; i++) new (&data[i]) T(pad);
    sz = size; }

template<class T>
void vec<T>::growTo(int size) {
    if (sz >= size) return;
    grow(size);
    for (int i = sz; i < size; i++) new (&data[i]) T();
    sz = size; }

template<class T>
void vec<T>::clear(bool dealloc) {
    if (data != NULL){
        for (int i = 0; i < sz; i++) data[i].~T();
        sz = 0;
        if (dealloc) free(data), data = NULL, cap = 0; } }


#endif