Compilare: main.cpp: In function 'int main()': main.cpp:9:21: warning: unused variable 'con1' [-Wunused-variable] int n,m,k,l,i,j,con1,con2,dr,last=0,mex,ii,k1,l1; ^~~~ main.cpp:9:26: warning: unused variable 'con2' [-Wunused-variable] int n,m,k,l,i,j,con1,con2,dr,last=0,mex,ii,k1,l1; ^~~~ main.cpp:9:31: warning: unused variable 'dr' [-Wunused-variable] int n,m,k,l,i,j,con1,con2,dr,last=0,mex,ii,k1,l1; ^~ main.cpp:9:34: warning: unused variable 'last' [-Wunused-variable] int n,m,k,l,i,j,con1,con2,dr,last=0,mex,ii,k1,l1; ^~~~ main.cpp:7:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("mexitate.in","r",stdin); ^ main.cpp:8:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("mexitate.out","w",stdout); ^ main.cpp:11:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ main.cpp:13:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&k,&l); ^ main.cpp:17:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v[i][j]); ^ main.cpp:9:41: warning: 'mex' may be used uninitialized in this function [-Wmaybe-uninitialized] int n,m,k,l,i,j,con1,con2,dr,last=0,mex,ii,k1,l1; ^~~