Compilare: user.cpp: In function ‘void refa()’: user.cpp:49:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (k=0;k<a[i][j].size();k++) ^ user.cpp: In function ‘void move_grid(int, int, int, int)’: user.cpp:79:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (cn1=0,i=x1,j=1;cn1+a[i][j].size()<y1;j++) ^ user.cpp:89:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (cn2=0,i=x2,j=1;cn2+a[i][j].size()<y2;j++) cn2 += a[i][j].size(); ^ user.cpp:75:13: warning: unused variable ‘k’ [-Wunused-variable] int i,j,k,cn1,cn2,ind1,ind2,val; ^ user.cpp: In function ‘void print()’: user.cpp:106:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (k=0;k<a[i][j].size();k++) ^ user.cpp: In function ‘int main()’: user.cpp:121:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&n,&t); ^ user.cpp:128:45: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d%d%d",&X1,&Y1,&X2,&Y2); ^