200. 岛屿数量c

int visit[300][300];

void dfs(char** grid,int m,int n,int i,int j){
    if(i>=m || j>=n) return;
    visit[i][j]=1;
    if( i+1<m &&  grid[i+1][j]=='1' && visit[i+1][j]==0 ){
        dfs(grid,m,n,i+1,j);
    }
    if( j+1<n  &&  grid[i][j+1] =='1' && visit[i][j+1] == 0){
        dfs(grid,m,n,i,j+1);
    }
    if( j-1 >=0 && grid[i][j-1]=='1' && visit[i][j-1] ==0  ) dfs(grid,m,n,i,j-1);
    if(i-1 >=0 && grid[i-1][j]=='1' && visit[i-1][j] ==0 ) dfs(grid,m,n,i-1,j);
}

int numIslands(char** grid, int gridSize, int* gridColSize) {
    int m=gridSize,n=gridColSize[0];
    for(int i=0;i<300;i++){
        for(int j=0;j<300;j++) visit[i][j]=0;
    }
    int count=0;
    for(int i=0;i<m;i++){
        for(int j=0;j<n;j++){
            if(grid[i][j]=='1'&& visit[i][j]==0){
                dfs(grid,m,n,i,j);
                count++;
            }
        }
    }
    return count;
}