/in/foo.cc:3:32: error: 'vector' has not been declared
     void search(int i, int j , vector<vector<int>>&flag,vector<vector<char>>&grid){
                                ^~~~~~
/in/foo.cc:3:38: error: expected ',' or '...' before '<' token
     void search(int i, int j , vector<vector<int>>&flag,vector<vector<char>>&grid){
                                      ^
/in/foo.cc:15:20: error: 'vector' has not been declared
     int numIslands(vector<vector<char>>& grid) {
                    ^~~~~~
/in/foo.cc:15:26: error: expected ',' or '...' before '<' token
     int numIslands(vector<vector<char>>& grid) {
                          ^
/in/foo.cc: In member function 'void Solution::search(int, int, int)':
/in/foo.cc:4:17: error: 'grid' was not declared in this scope
         while(i<grid.size()&&j<grid[i].size()&&i>=0&&j>=0){
                 ^~~~
/in/foo.cc:5:16: error: 'flag' was not declared in this scope
             if(flag[i][j]==1||grid[i][j]=='0'){
                ^~~~
/in/foo.cc:8:9: error: 'flag' was not declared in this scope
         flag[i][j]=1;//如果是未标记的陆地，则标记
         ^~~~
/in/foo.cc: In member function 'int Solution::numIslands(int)':
/in/foo.cc:16:9: error: 'vector' was not declared in this scope
         vector<vector<int>>flag;
         ^~~~~~
/in/foo.cc:16:23: error: expected primary-expression before 'int'
         vector<vector<int>>flag;
                       ^~~
/in/foo.cc:17:16: error: expected primary-expression before 'int'
         vector<int>x;
                ^~~
/in/foo.cc:18:16: error: expected primary-expression before 'int'
         vector<int>y;
                ^~~
/in/foo.cc:19:23: error: 'grid' was not declared in this scope
         for(int i=0;i<grid.size();i++){//如何给内嵌vector的vector用二维数组方式初始化赋值
                       ^~~~
/in/foo.cc:20:13: error: 'flag' was not declared in this scope
             flag.push_back(vector<int>());
             ^~~~
/in/foo.cc:20:35: error: expected primary-expression before 'int'
             flag.push_back(vector<int>());
                                   ^~~
/in/foo.cc:23:21: error: 'x' was not declared in this scope
                     x.push_back(i);
                     ^
/in/foo.cc:24:21: error: 'y' was not declared in this scope
                     y.push_back(j);  
                     ^
/in/foo.cc:30:17: error: 'x' was not declared in this scope
         while(i<x.size()){
                 ^
/in/foo.cc:31:16: error: 'flag' was not declared in this scope
             if(flag[x[i]][y[i]]==0&&grid[x[i]][y[i]]=='1'){
                ^~~~
/in/foo.cc:31:27: error: 'y' was not declared in this scope
             if(flag[x[i]][y[i]]==0&&grid[x[i]][y[i]]=='1'){
                           ^
/in/foo.cc:31:37: error: 'grid' was not declared in this scope
             if(flag[x[i]][y[i]]==0&&grid[x[i]][y[i]]=='1'){
                                     ^~~~