ACEC/circuit.cpp

#include "sweep.hpp"
#include "circuit.hpp"

bool Sweep::match_xor(int x) { // check clause x, -y, -z <==> xor
    int y = C[x][0], z = C[x][1];
    if (y >= 0 || z >= 0) return false;
    if (del[-y] || del[-z] || !C[-y].sz || !C[-z].sz) return false;
    int u1 = C[-y][0], v1 = C[-y][1];
    int u2 = C[-z][0], v2 = C[-z][1];
    if (u1 == -u2 && v1 == -v2) goto doit;
    if (u1 == -v2 && v1 == -u2) goto doit;
    return false;
doit:
    del[x] = 1;
    if (C[-y].outs <= 1) del[-y] = 2;
    if (C[-z].outs <= 1) del[-z] = 2;
    C[x][0] = C[-y][0], C[x][1] = C[-y][1];
    C[x].type = Xor;

    return true;
}

bool Sweep::match_majority(int x) {
    // x = -y & z
    // z = -v & -w
    // y = a1 & a2
    // v = a1 & a3
    // w = a2 & a3
    int y = C[x][0], z = C[x][1];
    if (y > 0) std::swap(y, z);
    if (y >= 0 || z <= 0) return false;
    if (del[-y] || del[z] || !C[-y].sz || !C[z].sz) return false;
    int v = C[z][0], w = C[z][1];
    if (v >= 0 || w >= 0) return false;
    if (del[-v] || del[-w] || !C[-v].sz || !C[-w].sz) return false;
    // -y, -w, -v
    int a = C[-y][0], b = C[-y][1];
    if (C[-v][1] == a || C[-v][1] == b) std::swap(C[-v][0], C[-v][1]);
    if (C[-w][1] == a || C[-w][1] == b) std::swap(C[-w][0], C[-w][1]);
    if (C[-v][0] != a && C[-w][0] != a) return false;
    if (C[-v][0] != b && C[-w][0] != b) return false;
    if (C[-v][1] != C[-w][1]) return false;
    del[x] = 1;
    if (C[-y].outs <= 1) del[-y] = 2;
    if (C[z].outs <= 1) del[z] = 2;
    if (C[-v].outs <= 1) del[-v] = 2;
    if (C[-w].outs <= 1) del[-w] = 2;

    C[x][0] = -a; C[x][1] = -b;
    C[x].push(-C[-w][1]);
    C[x].type = Majority;
    return true;
}

void Sweep::adjust_not() {
    int *pos = new int[maxvar + 1];
    int *neg = new int[maxvar + 1];
    for (int i = 1; i <= maxvar; i++)
        pos[i] = neg[i] = 0; 
    for (int i = 1; i <= maxvar; i++) {
        if (!C[i].sz || del[i] == 2) continue; 
        for (int j = 0; j < C[i].sz; j++) {
            int v = C[i][j];
            if (v > 0) pos[v]++;
            else neg[-v]++;
        }
    }
    for (int i = 1; i <= maxvar; i++) {
        if (!C[i].sz || del[i] == 2) continue; 
        if (C[i].type == Xor && pos[i] == 0 && neg[i] > 0) {
            for (int j = 0; j < C[i].sz; j++)
                if (C[i][j] < 0 && C[-C[i][j]].neg == 0) {C[i][j] = -C[i][j]; C[i].neg = 1; break;}
        } 
        // if (C[i].type == Xor) {
        //     int z = 0;
        //     for (int j = 0; j < C[i].sz; j++)
        //         if (C[i][j] < 0) {C[i][j] = -C[i][j]; z ^= 1;}
        //     if (z) C[i].neg = 1;
        // }     
    }
}

void Sweep::match_HA() {
    std::map<int, int> M;
    int lits = maxvar << 1 | 1;
    for (int i = 1; i <= maxvar; i++) {
        if (!C[i].sz || del[i] == 2 || C[i].type != And) continue; 
        int mapid = C[i][0] * lits + C[i][1];
        M[mapid] = i;
    }
    for (int i = 1; i <= maxvar; i++) {
        if (!C[i].sz || del[i] == 2 || C[i].type != Xor) continue;  
        int mapid = C[i][0] * lits + C[i][1];
        int id = M[mapid];
        if (id) {
            C[i].type = HA;
            C[i].carrier = id;
            del[id] = 2;
            continue;
        }

        mapid = (-C[i][0]) * lits - C[i][1];
        id = M[mapid];
        if (id) {
            C[i].type = HA;
            C[i].carrier = id;
            C[i][0] = -C[i][0];
            C[i][1] = -C[i][1];
            del[id] = 2;
            continue;
        }

        mapid = C[i][0] * lits - C[i][1];
        id = M[mapid];
        if (id) {
            C[i].type = HA;
            C[i].carrier = id;
            C[i][1] = -C[i][1];
            C[i].neg = 1;
            del[id] = 2;
            continue;
        }

        mapid = (-C[i][0]) * lits + C[i][1];
        id = M[mapid];
        if (id) {
            C[i].type = HA;
            C[i].carrier = id;
            C[i][0] = -C[i][0];
            C[i].neg = 1;
            del[id] = 2;
            continue;
        }
    }
}

bool Sweep::line_positive(int to) {
    return (to < 0) == C[abs(to)].neg;
}

void Sweep::recalculate_outs() {
    for (int i = 1; i <= maxvar; i++) 
        C[i].outs = 0;
    for (int i = 1; i <= maxvar; i++) {
        circuit *c = &C[i];
        if (!c->sz || del[i] == 2) continue; 
        for (int j = 0; j < c->sz; j++) {
            C[abs(c->to[j])].outs++;
        }
    }
}

void Sweep::match_FA() {
    for (int i = 1; i <= maxvar; i++) {
        circuit *c = &C[i];
        if (!c->sz || del[i] == 2) continue;
        if (c->type != HA) continue;
        C[abs(c->carrier)].to.clear();
        C[abs(c->carrier)].to.push(i);
        C[abs(c->carrier)].sz = 1;
        C[abs(c->carrier)].neg = c->carrier < 0;
    }

    for(int i=1; i<=maxvar; i++) {
        if (!C[i].sz || del[i] == 2) continue; 

        circuit *c = &C[i];

        if(c->type != And) continue;

        if(c->sz != 2) continue;

        if(c->to[0] >= 0) continue;
        if(c->to[1] >= 0) continue;

        if(C[abs(c->to[0])].sz != 1) continue;
        if(C[abs(c->to[1])].sz != 1) continue;

        int ha1 = C[abs(c->to[0])][0];
        int ha2 = C[abs(c->to[1])][0];

        ha1 = abs(ha1);
        ha2 = abs(ha2);

        if(C[ha1].type != HA) continue;
        if(C[ha2].type != HA) continue;

        bool check_link = true;
        for(int k=0; k<C[ha1].sz; k++) {
            int t = C[ha1].to[k];
            if(abs(t) == ha2) std::swap(ha1, ha2);
            if(abs(t) == ha2 && !line_positive(t))
                check_link = false;
        }
        for(int k=0; k<C[ha2].sz; k++) {
            int t = C[ha2].to[k];
            if(abs(t) == ha1 && !line_positive(t))
                check_link = false;
        }

        if(!check_link) continue;

        //printf("FA %d(%d) %d(%d)\n", ha1, C[ha1].neg, ha2, C[ha2].neg);

        if(C[ha1].outs == 2) del[ha1] = 2;

        circuit* fa = &C[ha2];
        fa->type = FA;
        fa->carrier = -i;
        vec<int> new_vec;
        for(int k=0; k<C[ha1].sz; k++) {
            int t = C[ha1].to[k];
            if(abs(t) == ha2) continue;
            new_vec.push(t);
            //printf("push: %d\n", t);
        }
        for(int k=0; k<C[ha2].sz; k++) {
            int t = C[ha2].to[k];
            if(abs(t) == ha1) continue;
            //printf("push: %d\n", k, t);
            new_vec.push(t);
        }
        new_vec.copyTo(fa->to);
        fa->sz = fa->to.size();

        C[i].to.clear();
        C[i].sz = 0;
        C[i].neg = !C[i].neg;
    }
}

void Sweep::to_multi_input_gates() {
    //printf("hello\n %d\n", maxvar);
    std::queue<int> q;
    q.push(maxvar);
    while(!q.empty()) {
        int u = q.front();
        q.pop();

        circuit *c = &C[u];

        if(u == maxvar) {
            for(int i=0; i<c->sz; i++) {
                if (!C[abs(c->to[i])].sz || del[abs(c->to[i])] == 2) continue;
                q.push(abs(c->to[i]));
            }
            continue;
        }
        
        for(int i=0; i<c->sz; i++) {
            circuit *t = &C[abs(c->to[i])];
            if(t->type != c->type) continue;
            vec<int> new_vec;
            if(c->type == Xor) {
                //printf("XOR: %d %d\n", u, c->to[i]);
                for(int j=0; j<t->sz; j++) {
                    new_vec.push(t->to[j]);
                    //printf("add %d\n", t->to[j]);
                }
                
                for(int j=0; j<c->sz; j++) {
                    if(i == j) {
                        if(!line_positive(c->to[j]))
                            new_vec[0] = -new_vec[0];
                    } else {
                        new_vec.push(c->to[j]);
                    }
                }

                if(t->outs == 1) {
                    del[abs(c->to[i])] = 2;
                    //printf("del: %d\n", c->to[i]);
                }

                new_vec.copyTo(c->to);
                c->sz = new_vec.size();

                q.push(u);
                break;
            }

            if(c->type == And && line_positive(c->to[i])) {
                if(t->to.size() == 0) continue;

                //printf("AND: %d %d\n", u, c->to[i]);
                t->to.copyTo(new_vec);
                //printf("new_vec %d\n", new_vec.size());

                for(int j=0; j<c->sz; j++) {
                    if(i != j) {
                        new_vec.push(c->to[j]);
                    }
                }

                if(C[abs(c->to[i])].outs == 1)  {
                    del[abs(c->to[i])] = 2;
                }

                new_vec.copyTo(c->to);
                c->sz = new_vec.size();

                q.push(u);

                break;
            }
        }

        

        for(int i=0; i<c->sz; i++) {
            if (!C[abs(c->to[i])].sz || del[abs(c->to[i])] == 2) continue;
            q.push(abs(c->to[i]));
        }
    }
}

void Sweep::to_dot_graph(const char* filename, int end_point) {
    std::ofstream file(filename);
    std::queue<int> q;
    q.push(abs(end_point));
    std::set<int> used;
    used.insert(abs(end_point));
    file << "digraph \"graph\" {\n";

    char str[1024];

    while(!q.empty()) {
        int u = q.front();
        q.pop();
        circuit *c = &C[u];

        if(!c->sz || del[u] == 2) continue;

        sprintf(str, "A%d[label=\"%d (%s)\"];\n", u, u, gate_type[c->type].c_str());
        file << str;
        if (c->type == HA || c->type == FA) {
            int a = u * (C[u].neg ? -1 : 1);
            int b = c->carrier;
            sprintf(str, "A%d->A%d[arrowhead=%s]\n", u, abs(b), !line_positive(b) ? "dot" : "none");
            file << str;
        }
        else {
            int t = u * (C[u].neg ? -1 : 1);
        }
        for (int j = 0; j < c->sz; j++) {
            /**
             * 删除初始输入
            */
            if(abs(c->to[j]) <= 14) continue;

            sprintf(str, "A%d->A%d[arrowhead=%s]\n", abs(c->to[j]), u, !line_positive(c->to[j]) ? "dot" : "none");
            file << str;
        }

        for(int j=0; j<c->sz; j++) {
            int x = abs(c->to[j]);
            if(used.count(x)) continue;
            used.insert(x);
            q.push(x);
        }
    }
    
    file << "}\n";
}

void Sweep::identify() {
    
    del = new int[maxvar + 1];
    for (int i = 1; i <= maxvar; i++) del[i] = 0;
    recalculate_outs();
    for (int i = 1; i <= maxvar; i++) {
        if (!C[i].sz || del[i] == 2) continue;
        if (match_xor(i)) continue;
    }
    
    // recalculate_outs();

    // for (int i = 1; i <= maxvar; i++) {
    //     if (!C[i].sz || del[i] == 2) continue;
    //     if (match_majority(i)) continue;
    // }

    recalculate_outs();
    //adjust_not();
    //match_HA();

    //to_multi_input_gates();
    //match_FA();

    // printf("digraph \"graph\" {\n");
    // for (int i = 1; i <= maxvar; i++) {
    //     circuit *c = &C[i];
    //     if (!c->sz || del[i] == 2) continue;

    //     printf("A%d[label=\"%d (%s)\"];\n", i, i, gate_type[c->type].c_str());

    //     if (c->type == HA || c->type == FA) {
    //         int a = i * (C[i].neg ? -1 : 1);
    //         int b = c->carrier;
    //         printf("A%d->A%d[arrowhead=%s]\n", i, abs(b), !line_positive(b) ? "dot" : "none");
    //     }
    //     else {
    //         int t = i * (C[i].neg ? -1 : 1);
    //     }
    //     for (int j = 0; j < c->sz; j++) {
    //         if(abs(c->to[j]) <= 14) continue;
    //         printf("A%d->A%d[arrowhead=%s]\n", abs(c->to[j]), i, !line_positive(c->to[j]) ? "dot" : "none");
    //     }
    // }
    // printf("}\n");

    recalculate_outs();
    // for (int i = 1; i <= maxvar; i++) {
    //     circuit *c = &C[i];
    //     if (!c->sz || del[i] == 2) continue;
        
    //     if (c->type == HA || c->type == FA)
    //         printf("( %d %d )", i * (C[i].neg ? -1 : 1), c->carrier); 
    //     else
    //         printf("%d", i * (C[i].neg ? -1 : 1));

    //     printf(" = %s ( ", gate_type[c->type].c_str());

    //     for (int j = 0; j < c->sz; j++) {
    //         printf("%d ", c->to[j]);
    //     }

    //     puts(")");
    // }

    inv_C = new vec<int>[maxvar + 1];
    for (int i = 1; i <= maxvar; i++) {
        circuit *c = &C[i];
        if (!c->sz || del[i] == 2) continue; 
        for (int j = 0; j < c->sz; j++) {
            inv_C[abs(c->to[j])].push(i);
        }
    }
    // to_dot_graph("graph1.dot", 291);
    // to_dot_graph("graph2.dot", 175);

    // recalculate_outs();
    // for (int i = 1; i <= maxvar; i++) {
    //     circuit *c = &C[i];
    //     if (del[i] == 2) continue; 
    //     printf("%d : %d (outs)\n", i, c->outs);
    // }
    
}