View Compilation Error

0_0_29550213_29796.cpp: In function 'int main()':
0_0_29550213_29796.cpp:74:31: error: 'sort' was not declared in this scope
         sort(a, a + t + 1, cmp);
                               ^
0_0_29550213_29796.cpp:74:31: note: suggested alternative:
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/algorithm:62:0,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/x86_64-w64-mingw32/bits/stdc++.h:64,
                 from 0_0_29550213_29796.cpp:1:
GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_algo.h:4705:5: note:   'std::sort'
     sort(_RandomAccessIterator __first, _RandomAccessIterator __last,
     ^