View Compilation Error

0_0_18314895_27711.cpp:20:1: error: 'bitset' does not name a type
 bitset<90>dp[20];
 ^
0_0_18314895_27711.cpp: In function 'int dpp(int, int, int)':
0_0_18314895_27711.cpp:24:18: error: 'dp' was not declared in this scope
     FOR(i, 0, n) dp[i].reset();
                  ^
0_0_18314895_27711.cpp:25:5: error: 'dp' was not declared in this scope
     dp[0][0] =1;
     ^