<<Crystal>> Underground Switches

// 3 2 1 is optimal, this program proves it.

#include <stdio.h>

int MASK_4  = 1 << 4;
int MASK_5  = 1 << 5;
int MASK_6  = 1 << 6;
int MASK_7  = 1 << 7;
int MASK_8  = 1 << 8;
int MASK_9  = 1 << 9;
int MASK_10 = 1 << 10;
int MASK_11 = 1 << 11;
int MASK_12 = 1 << 12;
int MASK_13 = 1 << 13;
int MASK_14 = 1 << 14;

void printBits(size_t const size, void const * const ptr)
{
    unsigned char *b = (unsigned char*) ptr;
    unsigned char byte;
    int i, j;

    for (i = size-1; i >= 0; i--) {
        for (j = 7; j >= 0; j--) {
            byte = (b[i] >> j) & 1;
            printf("%u", byte);
        }
    }
    puts("");
}

int isDoorsMatching(int doors, int mask){
   return (doors&mask) == mask;
}

int isDoorsInPaths(int doors, int* paths, int size){
    int isIn = 1;

    for(int i = 0; i < size; i++){
        if(isDoorsMatching(doors, paths[i]))
            return isIn;
    }

    return !isIn;
}

int updateCombination(int oldCombination, int score){
    int clearAll = 0b000000000000000;

    int newCombination = oldCombination;
    switch(score){
        case 0:
            newCombination &= clearAll;
            break;
        case 1:
            newCombination |= (MASK_4|MASK_10|MASK_13);
            newCombination &= ((~(MASK_9|MASK_11|MASK_12|MASK_14))&0xFFFF);
            break;
        case 2:
            newCombination |= (MASK_5|MASK_11|MASK_12);
            newCombination &= ((~(MASK_8|MASK_10|MASK_13|MASK_14))&0xFFFF);
            break;
        case 3:
            newCombination |= (MASK_6|MASK_10|MASK_13);
            newCombination &= ((~(MASK_7|MASK_11|MASK_12|MASK_14))&0xFFFF);
            break;
        case 4:
            newCombination |= (MASK_7|MASK_11|MASK_12);
            newCombination &= ((~(MASK_6|MASK_10|MASK_13|MASK_14))&0xFFFF);
            break;
        case 5:
            newCombination |= (MASK_8|MASK_10|MASK_13);
            newCombination &= ((~(MASK_5|MASK_11|MASK_12|MASK_14))&0xFFFF);
            break;
        default: //6
            newCombination |= (MASK_9|MASK_11|MASK_12|MASK_14);
            newCombination &= ((~(MASK_4|MASK_10|MASK_13))&0xFFFF);
            break;
    }

    return newCombination;
}

int calculateCombination(int* doors, int doorsNb){
    int isZeroEncountered = 0;
    int combination = 0;
    int score = 0;
    int switches[] = {0, 0, 0, 0}; // index 0 is usused

    for(int i = 0; i < doorsNb; i++){
        int door = doors[i];

        if(isZeroEncountered && door > 0)
            return 0;

        if(door == 0){
            isZeroEncountered = 1;
            continue;
        }

        int switchh = switches[door];
        //printf("b %d %d %d\n", door, switchh, score);
        if(switchh == 0){
            switches[door] = 1;
            score += door;
        } else {
            switches[door] = 0;
            score -= door;
        }

        //printf("a %d %d %d\n", door, switches[door], score);
        combination = updateCombination(combination, score);
    }

    return combination;
}


int go()
{
    /* 6    5    4
    /*   11   10
    /* 7    8    9
    /*   13   12   14
    */

    int PATHS[] = {
        MASK_4 |MASK_9 |MASK_14,
        MASK_4 |MASK_10 |MASK_8 |MASK_12 |MASK_14,
        MASK_4 |MASK_10 |MASK_11 |MASK_7 |MASK_13 |MASK_12 |MASK_14,

        MASK_5 |MASK_10 |MASK_9 |MASK_14,
        MASK_5 |MASK_11 |MASK_8 |MASK_12 |MASK_14,
        MASK_5 |MASK_11 |MASK_7 |MASK_13 |MASK_12 |MASK_14,

        MASK_6 |MASK_11 |MASK_10 |MASK_9 |MASK_14,
        MASK_6 |MASK_11 |MASK_8 |MASK_12 |MASK_14,
        MASK_6 |MASK_7 |MASK_13 |MASK_12 |MASK_14,
        MASK_6 |MASK_7 |MASK_13 |MASK_8 |MASK_10 |MASK_9 |MASK_14
    };
    int PATHS_NB = sizeof(PATHS) / sizeof(int);

    int doors[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
    int doorsNb = sizeof(doors) / sizeof(int);
    int firstDoorIndex = 0;


    // LOL : i don't know how to recurse ...
    for(int a = 0; a <= 3; a++){
        doors[0]=a;
        for(int b = 0; b <= 3; b++){
            doors[1]=b;
            for(int c = 0; c <= 3; c++){
                doors[2]=c;
                for(int d = 0; d <= 3; d++){
                    doors[3]=d;
                    for(int e = 0; e <= 3; e++){
                        doors[4]=e;
                        for(int f = 0; f <= 3; f++){
                            doors[5]=f;
                            for(int g = 0; g <= 3; g++){
                                doors[6]=g;
                                for(int h = 0; h <= 3; h++){
                                    doors[7]=h;
                                    for(int i = 0; i <= 3; i++){
                                        doors[8]=i;
                                        for(int j = 0; j <= 3; j++){
                                            doors[9]=j;
                                            for(int k = 0; k <= 3; k++){
                                                doors[10]=k;
                                                for(int l = 0; l <= 3; l++){
                                                    doors[11]=l;
                                                    int combination = calculateCombination(doors, doorsNb);
                                                    if(isDoorsInPaths(combination, PATHS, PATHS_NB)){
                                                        printf("%d %d %d %d %d %d %d %d %d %d %d %d - ", doors[0], doors[1], doors[2], doors[3], doors[4],doors[5],
                                                                                                        doors[6], doors[7], doors[8], doors[9], doors[10],doors[11]);
                                                        printBits(sizeof(combination),&combination);
                                                    }
                                                }
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
    }

    printf("Done.\n");
}

int main(){
    go();
    //printf("%x %x", updateCombination(0, 1), 0b10010000010000);
}