View Compilation Error

0_0_16464907_1467.cpp: In function 'void gao()':
0_0_16464907_1467.cpp:35:27: error: 'memset' was not declared in this scope
     memset(dp,0,sizeof(dp));
                           ^
0_0_16464907_1467.cpp:44:62: error: 'max' was not declared in this scope
                 dp[i][j] = max(dp[i][j], dp[i-1][k]+num[i][j]);
                                                              ^
0_0_16464907_1467.cpp:50:33: error: 'max' was not declared in this scope
         ans = max(ans,dp[n-1][i]);
                                 ^
0_0_16464907_1467.cpp:52:22: error: 'printf' was not declared in this scope
     printf("%d\n",ans);
                      ^
0_0_16464907_1467.cpp: In function 'int main()':
0_0_16464907_1467.cpp:57:19: error: 'gets' was not declared in this scope
     while(gets(str)){
                   ^
0_0_16464907_1467.cpp:91:17: error: 'getchar' was not declared in this scope
         getchar();
                 ^