View Compilation Error

0_0_29874940_2619.cpp:31:1: error: 'vector' does not name a type
 vector<int> Ncolor;
 ^
0_0_29874940_2619.cpp: In function 'int main()':
0_0_29874940_2619.cpp:69:28: error: expected ')' before ';' token
   for(int i = 1; i; i <= 50; i++){
                            ^
0_0_29874940_2619.cpp:69:30: error: 'i' was not declared in this scope
   for(int i = 1; i; i <= 50; i++){
                              ^
0_0_29874940_2619.cpp:76:7: error: 'Ncolor' was not declared in this scope
   if (Ncolor.size() == 0) {
       ^