View Compilation Error

0_0_33607143_15038.cpp: In function 'void solve()':
0_0_33607143_15038.cpp:10:25: error: 'strlen' was not declared in this scope
     int n = strlen(s + 1);
                         ^
0_0_33607143_15038.cpp:26:28: error: 'sort' was not declared in this scope
     sort(a.begin(), a.end());
                            ^