7777class Solution {
7878 int zeros = 0 ;
7979 private int callme (int x , int y , int [][] grid ){
80- if (x <0 || y <0 || x >=grid .length || y >=grid [0 ].length )
80+ if (x <0 || y <0 || x >=grid .length || y >=grid [0 ].length || grid [ x ][ y ] == - 1 || grid [ x ][ y ] == 3 )
8181 return 0 ;
82- if (grid [x ][y ] == -1 || grid [x ][y ] == 3 )
83- return 0 ;
84- if (grid [x ][y ] == 2 ){
85- if (zeros == 0 )
86- return 1 ;
87- else
88- return 0 ;
89- }
9082
91- zeros --;
92- grid [x ][y ] = 3 ;
83+ if (grid [x ][y ] == 2 )
84+ return zeros == 0 ? 1 : 0 ;
85+ 9386 int ret = 0 ;
9487
88+ grid [x ][y ] = 3 ;
89+ zeros --;
90+ 9591 //left
9692 ret += callme (x , y -1 , grid );
9793 //right
@@ -103,23 +99,24 @@ private int callme(int x, int y, int[][] grid){
10399
104100 zeros ++;
105101 grid [x ][y ] = 0 ;
102+ 106103 return ret ;
107104 }
108105
109106 public int uniquePathsIII (int [][] grid ) {
110107
108+ int x = 0 , y = 0 ;
111109 for (int i =0 ; i <grid .length ; i ++)
112110 for (int j =0 ; j <grid [0 ].length ; j ++)
113111 if (grid [i ][j ] == 0 )
114112 zeros ++;
115- for (int i =0 ; i <grid .length ; i ++)
116- for (int j =0 ; j <grid [0 ].length ; j ++)
117- if (grid [i ][j ] == 1 ){
118- grid [i ][j ] = -1 ;
119- return callme (i +1 , j , grid )+callme (i -1 , j , grid )+callme (i , j -1 , grid )+callme (i , j +1 , grid );
113+ else if (grid [i ][j ] == 1 ){
114+ x = i ;
115+ y = j ;
120116 }
121117
122- return 0 ;
118+ grid [x ][y ] = -1 ;
119+ return callme (x +1 , y , grid )+callme (x -1 , y , grid )+callme (x , y -1 , grid )+callme (x , y +1 , grid );
123120 }
124121}
125122// @lc code=end
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