#include <stdio.h> #include<stdlib.h> //used for 'exit' in error statements #define INPUT "A.txt" FILE *ifp; char x[26000]; main() { int a, b, c, d, i, j; if ( (ifp=fopen(INPUT,"r")) == NULL) {printf("Cannot open %s file.\n",INPUT); exit;} for(j = 1;; j++) { fscanf(ifp, " %d %d %d %d", &a, &b, &c, &d); if(a < 0) break; a = (a + 368 - d) % 23; b = (b + 392 - d) % 28; c = (c + 396 - d) % 33; memset(x, 0, sizeof(x)); for(i = b; i < 25000; i += 28) x[i]++; for(i = c; i < 25000; i += 33) x[i]++; for(i = a ? a : 23; i < 25000 && x[i] != 2; i += 23); printf("Case %d: the next triple peak occurs in %d days.\n", j, i); } }