Compilare: main.cpp: In function 'int main()': main.cpp:109:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pirati.in","r",stdin); ^ main.cpp:110:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pirati.out","w",stdout); ^ main.cpp:114:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d\n",&n,&m,&q); ^ main.cpp:117:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%c",&ch),a[i][j]=ch-'0'; ^ main.cpp:115:2: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] for(i=1;i<=n;++i,scanf("\n")) ^~~ main.cpp:121:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d",&x1,&y1,&x2,&y2); ^