View Compilation Error

0_0_20054643_10157.cpp: In function 'int MaxMatch()':
0_0_20054643_10157.cpp:33:30: error: 'memset' was not declared in this scope
     memset(cx,0xff,sizeof(cx)); //从0 匹配开始增广,将cx 和cy 各元素初始化为-1  
                              ^
0_0_20054643_10157.cpp: In function 'int main()':
0_0_20054643_10157.cpp:52:29: error: 'memset' was not declared in this scope
         memset(g,0,sizeof(g));  
                             ^