magic5x5.c

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>

/*
IPQkm
XhUjv
SogLr
YNtfW
abcdE
*/

#define THREADS 6

#define CONDITION_START(a, A, B, C, D)   a = 65 - A - B - C - D; if (used[a] == 0) { used[a] = 1;
#define LOOP_START(a)                    for (a = 1; a <= 25; a++) { if (used[a]) continue; used[a] = 1;
#define END(a)                           used[a] = 0; }

int compute(int startValue) {
    int usedArray[200];
    int *used = usedArray + 100;
    for (int i = -100; i < 100; i++)
        used[i] = (i >= 1 && i <= 25) ? 0 : 1;
    int a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y;
    a=b=c=d=e=f=g=h=i=j=k=l=m=n=o=p=q=r=s=t=u=v=w=x=y=0;
    int count = 0;

    LOOP_START(a)
    for (b = startValue; b <= 25; b += THREADS) { if (used[b]) continue; used[b] = 1;
    LOOP_START(c)
    LOOP_START(d)
    CONDITION_START(e, a, b, c, d)

    if (e < a) {
        used[e] = 0;
        used[d] = 0;
        continue;
    }

    LOOP_START(f)
    LOOP_START(g)
    LOOP_START(h)
    CONDITION_START(i, h, g, f, e)

    if (i < a || i < e) {
        used[i] = 0;
        used[h] = 0;
        continue;
    }

    LOOP_START(j)
    LOOP_START(k)
    CONDITION_START(l, k, j, f, d)
    LOOP_START(m)

    if (m < a) {
        used[m] = 0;
        continue;
    }

    CONDITION_START(n, a, g, j, m)
    LOOP_START(o)
    CONDITION_START(p, h, o, n, b)
    CONDITION_START(q, i, p, k, m)
    LOOP_START(r)
    CONDITION_START(s, o, g, l, r)
    LOOP_START(t)
    CONDITION_START(u, q, g, t, c)
    LOOP_START(v)
    CONDITION_START(w, m, v, r, e)
    CONDITION_START(x, h, u, j, v)
    y = 65 - i - x - s - a;

    count++;

    END(x)
    END(w)
    END(v)
    END(u)
    END(t)
    END(s)
    END(r)
    END(q)
    END(p)
    END(o)
    END(n)
    END(m)
    END(l)
    END(k)
    END(j)
    END(i)
    END(h)
    END(g)
    END(f)
    END(e)
    END(d)
    END(c)
    END(b)
    END(a)

    count *= 8;
    return count;
}

void *threadFunc(void *argument) {
    int threadId = *((int*)argument);
    int *result = calloc(1, sizeof(int));
    *result = compute(threadId + 1);
    return result;
}

int main() {
    int arguments[THREADS];
    pthread_t threads[THREADS];
    int *results[THREADS];
    for (int i = 0; i < THREADS; i++)
        arguments[i] = i;
    for (int i = 0; i < THREADS; i++)
        pthread_create(&threads[i], NULL, threadFunc, &arguments[i]);
    for (int i = 0; i < THREADS; i++)
        pthread_join(threads[i], (void **)&results[i]);

    int count = 0;
    for (int i = 0; i < THREADS; i++) {
        count += *results[i];
        free(results[i]);
    }
    printf("%u\n", (unsigned)count);
    return 0;
}