Compilare: main.c: In function 'main': main.c:46:3: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf( fin, "%d", &a ); ^~~~~~~~~~~~~~~~~~~~~~~ main.c:47:3: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf( fin, "%d", &b ); ^~~~~~~~~~~~~~~~~~~~~~~ main.c:40:13: warning: iteration 49998 invokes undefined behavior [-Waggressive-loop-optimizations] if (ciur[i] == 0) { ~~~~^~~ main.c:39:3: note: within this loop for (i = 2; i <= 50000; ++i ) { ^~~