标签:style blog color os io ar for 2014 art
It‘s still an Amazon interview question.
Given an array containing only stars ‘*‘ and hashes ‘#‘ . Find longest contiguous sub array that will contain equal no. of stars ‘*‘ and hashes ‘#‘.
Think for a while......
Typical DP-solved question.
1 /************************************************* 2 Author:Zhou You 3 Time:2014.09.09 4 *************************************************/ 5 #include <iostream> 6 #include <cstdio> 7 8 using namespace std; 9 10 struct matrix_element 11 { 12 public: 13 matrix_element(): 14 star_num_(0), 15 hash_num_(0){} 16 17 matrix_element(unsigned star_num,unsigned hash_num): 18 star_num_(star_num), 19 hash_num_(hash_num){ 20 } 21 22 unsigned star_num_; 23 unsigned hash_num_; 24 }; 25 26 void BuildMatrix(matrix_element *** pmaze,unsigned row_num,unsigned column_num) 27 { 28 *pmaze = new matrix_element*[row_num]; 29 for(unsigned i=0;i<row_num;++i){ 30 (*pmaze)[i] = new matrix_element[column_num]; 31 } 32 } 33 34 void ReleaseMatrix(matrix_element ***pmaze,unsigned row_num) 35 { 36 if(!pmaze) return; 37 38 for(unsigned i=0;i<row_num;++i){ 39 delete [](*pmaze)[i]; 40 } 41 42 delete [](*pmaze); 43 } 44 45 void CoreSolve(char **parray,unsigned element_num) 46 { 47 matrix_element **pnote = NULL; 48 BuildMatrix(&pnote,element_num,element_num); 49 50 for(unsigned i=0;i<element_num;++i){ 51 if((*parray)[i]==‘*‘){ 52 ++pnote[i][i].star_num_; 53 }else if((*parray)[i]==‘#‘){ 54 ++pnote[i][i].hash_num_; 55 } 56 } 57 58 int index_start = -1,index_end = -1; 59 unsigned cur_length = 0; 60 61 for(unsigned sub_array_length = 2;sub_array_length<=element_num;++sub_array_length){ 62 for(unsigned i=0;i<=element_num-sub_array_length;++i){ 63 pnote[i][i+sub_array_length-1].hash_num_ = 64 pnote[i][i+sub_array_length-2].hash_num_+ 65 pnote[i+sub_array_length-1][i+sub_array_length-1].hash_num_; 66 67 pnote[i][i+sub_array_length-1].star_num_ = 68 pnote[i][i+sub_array_length-2].star_num_+ 69 pnote[i+sub_array_length-1][i+sub_array_length-1].star_num_; 70 71 if(pnote[i][i+sub_array_length-1].star_num_== 72 pnote[i][i+sub_array_length-1].hash_num_){ 73 if(sub_array_length>cur_length){ 74 cur_length = sub_array_length; 75 index_start = i; 76 index_end = i+sub_array_length-1; 77 } 78 } 79 } 80 } 81 82 cout<<index_start<<" "<<index_end; 83 84 ReleaseMatrix(&pnote,element_num); 85 } 86 87 void Solve() 88 { 89 unsigned element_num = 0; 90 cin>>element_num; 91 92 char *parray = new char[element_num]; 93 for(unsigned i=0;i<element_num;++i){ 94 cin>>parray[i]; 95 } 96 97 CoreSolve(&parray,element_num); 98 delete []parray; 99 } 100 101 int main() 102 { 103 freopen("data.in","r",stdin); 104 freopen("data.out","w",stdout); 105 106 unsigned case_num = 0; 107 cin>>case_num; 108 109 for(unsigned i=1;i<=case_num;++i){ 110 cout<<"Case #"<<i<<" "; 111 Solve(); 112 cout<<endl; 113 } 114 115 return 0; 116 }
Case in data.in file
5 4 *#*# 4 *#** 5 ***** 6 *###** 12 ****###*****
Output data in data.out file
Case #1 0 3 Case #2 0 1 Case #3 -1 -1 Case #4 0 5 Case #5 1 6
Find longest contiguous sub array
标签:style blog color os io ar for 2014 art
原文地址:http://www.cnblogs.com/zhouyoulie/p/3963327.html