@@ -74,43 +74,45 @@ We can reach the end from starting indexes 1, 2, and 4.
7474*/
7575
7676int smallest_among_greaters (int k , int * map , int sz ) {
77- for (int i = k ; i < sz ; i ++ ) {
78- if (map [i ] != 0 ) return map [i ];
79- }
80- return 0 ;
77+ for (int i = k ; i < sz ; i ++ ) {
78+ if (map [i ] != 0 ) return map [i ];
79+ }
80+ return 0 ;
8181}
8282int greatest_among_smallers (int k , int * map , int sz ) {
83- for (int i = k ; i >= 0 ; i -- ) {
84- if (map [i ] != 0 ) return map [i ];
85- }
86- return 0 ;
87- 83+ for (int i = k ; i >= 0 ; i -- ) {
84+ if (map [i ] != 0 ) return map [i ];
85+ }
86+ return 0 ;
87+ }
8888int oddEvenJumps (int * A , int ASize ){
89- int map [100000 ] = { 0 };
90- 91- #define sz (sizeof(map)/sizeof(map[0]))
92- 93- int hi [20000 ] = { 0 }, lo [20000 ] = { 0 };
94- 95- int i , h , l , ans ;
96- 97- hi [ASize - 1 ] = lo [ASize - 1 ] = 1 ;
98- map [A [ASize - 1 ]] = ASize ; // 1 - ASize
99- ans = 1 ;
100- 101- for (i = ASize - 2 ; i >= 0 ; i -- ) {
102- h = smallest_among_greaters (A [i ], map , sz );
103- l = greatest_among_smallers (A [i ], map , sz );
104- if (h && lo [h - 1 ]) { hi [i ] = 1 ; ans ++ ; }
105- if (l && hi [l - 1 ]) lo [i ] = 1 ;
106- map [A [i ]] = i + 1 ;
107- }
108- 109- return ans ;
89+ // if jump can to to a high or low number on current index
90+ bool hi [20000 ] = { false }, lo [20000 ] = { false };
91+ 92+ // index of a number is on
93+ int map [100000 ] = { 0 };
94+ #define sz (sizeof(map) / sizeof(map[0]))
95+ 96+ int i , h , l , ans ;
97+ 98+ hi [ASize - 1 ] = lo [ASize - 1 ] = true;
99+ 100+ map [A [ASize - 1 ]] = ASize ; // index + 1
101+ 102+ ans = 1 ;
103+ 104+ for (i = ASize - 2 ; i >= 0 ; i -- ) {
105+ h = smallest_among_greaters (A [i ], map , sz );
106+ l = greatest_among_smallers (A [i ], map , sz );
107+ if (h && lo [h - 1 ]) { hi [i ] = true; ans ++ ; }
108+ if (l && hi [l - 1 ]) lo [i ] = true;
109+ map [A [i ]] = i + 1 ;
110+ }
111+ 112+ return ans ;
110113}
111114
112115
113- 114116/*
115117Difficulty:Hard
116118
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