sudoku.cpp: In function 'bool valid(int, int)': sudoku.cpp:19: warning: suggest explicit braces to avoid ambiguous 'else' sudoku.cpp:26: warning: suggest explicit braces to avoid ambiguous 'else' sudoku.cpp:35: warning: suggest explicit braces to avoid ambiguous 'else' sudoku.cpp:42: warning: suggest explicit braces to avoid ambiguous 'else' sudoku.cpp:48: warning: suggest explicit braces to avoid ambiguous 'else' sudoku.cpp:55: warning: suggest explicit braces to avoid ambiguous 'else' sudoku.cpp:62: warning: suggest explicit braces to avoid ambiguous 'else' sudoku.cpp:70: warning: suggest explicit braces to avoid ambiguous 'else' sudoku.cpp:76: warning: suggest explicit braces to avoid ambiguous 'else' sudoku.cpp: In function 'int main()': sudoku.cpp:124: warning: unused variable 'ct'