Compilare: main.c: In function 'main': main.c:19:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("pluton.in", "r", stdin); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:20:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("pluton.out", "w", stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:23:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &numberOfSoldiers); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:26:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%s", arr[i].soldierID); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~