Panasonic Software Engineer Inernship interview questions

On-campus code test. The test paper covers C, C++, Linux, Coding questions. Basic concepts of C, define C variables, concept explanation, write C function to output the value of a linked list in reverse order. Basic C++ concepts(can be alternated to Java). Coding part has 3 question. The second one is string permutation as the following interview question. The third one is to analyze the function of a code snippets, which I think is to count the number of 1s in the binary format of a integer.