GATE CS and IT 2013 Paper

Common Data for Questions 50 and 51:
The procedure given below is required to find and replace certain characters inside an input character string supplied in array A. The characters to be replaced are supplied in array oldc, while their respective replacement characters are supplied in array newc. Array A has a fixed length of five characters, while arrays oldc and newc contain three characters each. However, the procedure is flawed.
void find_and_replace (char *A, char *oldc, char *newc) {
for (int i = 0; i < 5; i++ )
for ( int j = 0; j < 3; j++ )
if ( A [i] == oldc [j] ) A[i] = newc [j];
}
The procedure is tested with the following four test cases
(1) oldc = “abc”, newc = “dab” (2) oldc = “cde”, newc = “bcd”
(3) oldc = “bca”, newc = “cda” (4) oldc = “abc”, newc = “bac”