submatrix.cpp: In function `int main()': submatrix.cpp:7: warning: unused variable `int smax' submatrix.cpp:5: warning: `int l1' might be used uninitialized in this function submatrix.cpp:5: warning: `int l2' might be used uninitialized in this function submatrix.cpp:5: warning: `int c1' might be used uninitialized in this function submatrix.cpp:5: warning: `int c2' might be used uninitialized in this function