submatrix.cpp: In function `int main()': submatrix.cpp:4: warning: unused variable `int pp' submatrix.cpp:4: warning: unused variable `int i2' submatrix.cpp:4: warning: unused variable `int j2' submatrix.cpp:4: warning: `int p1' might be used uninitialized in this function submatrix.cpp:4: warning: `int p2' might be used uninitialized in this function submatrix.cpp:4: warning: `int p3' might be used uninitialized in this function submatrix.cpp:4: warning: `int p4' might be used uninitialized in this function