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| 1 | +#include<iostream> |
| 2 | +using namespace std; |
| 3 | +int editdistance_dp(string s,string t){ |
| 4 | + int m=s.size(); |
| 5 | + int n=t.size(); |
| 6 | + int **output=new int*[m+1]; |
| 7 | + for(int i=0;i<=m;i++){ |
| 8 | + output[i]=new int[n+1]; |
| 9 | + } |
| 10 | + for(int j=0;j<=n;j++){ |
| 11 | + output[0][j]=j; |
| 12 | + } |
| 13 | + for(int i=1;i<=m;i++){ |
| 14 | + output[i][0]=i; |
| 15 | + } |
| 16 | + for(int i=1;i<=m;i++){ |
| 17 | + for(int j=1;j<=n;j++){ |
| 18 | + if(s[m-i]==t[n-j]){ |
| 19 | + output[i][j]=output[i-1][j-1]; |
| 20 | + } |
| 21 | + else{ |
| 22 | + int a=output[i-1][j]+1; |
| 23 | + int b=output[i][j-1]+1; |
| 24 | + int c=output[i-1][j-1]+1; |
| 25 | + output[i][j]=min(a,min(b,c)); |
| 26 | + } |
| 27 | + } |
| 28 | + } |
| 29 | + return output[m][n]; |
| 30 | +} |
| 31 | +int editdistance_mem(string s,string t,int **output){ |
| 32 | + int m=s.size(); |
| 33 | + int n=t.size(); |
| 34 | + if(s.size()==0||t.size()==0){ |
| 35 | + return max(s.size(),t.size()); |
| 36 | + } |
| 37 | + if(output[m][n]!=-1){ |
| 38 | + return output[m][n]; |
| 39 | + } |
| 40 | + int ans; |
| 41 | + if(s[0]==t[0]){ |
| 42 | + ans=editdistance_mem(s.substr(1),t.substr(1),output); |
| 43 | + } |
| 44 | + else{ |
| 45 | + int a=editdistance_mem(s.substr(1),t,output)+1; |
| 46 | + int b=editdistance_mem(s,t.substr(1),output)+1; |
| 47 | + int c=editdistance_mem(s.substr(1),t.substr(1),output)+1; |
| 48 | + ans=min(a,min(b,c)); |
| 49 | + } |
| 50 | + output[m][n]=ans; |
| 51 | + return output[m][n]; |
| 52 | +} |
| 53 | +int editdistance_mem(string s,string t){ |
| 54 | + int m=s.size(); |
| 55 | + int n=t.size(); |
| 56 | + int **output=new int*[m+1]; |
| 57 | + for(int i=0;i<=m;i++){ |
| 58 | + output[i]=new int[n+1]; |
| 59 | + for(int j=0;j<=n;j++){ |
| 60 | + output[i][j]=-1; |
| 61 | + } |
| 62 | + } |
| 63 | + return editdistance_mem(s,t,output); |
| 64 | +} |
| 65 | +int editdistance(string s,string t){ |
| 66 | + if(s.size()==0||t.size()==0){ |
| 67 | + return max(s.size(),t.size()); |
| 68 | + } |
| 69 | + if(s[0]==t[0]){ |
| 70 | + return editdistance(s.substr(1),t.substr(1)); |
| 71 | + } |
| 72 | + else{ |
| 73 | + int a=editdistance(s.substr(1),t); |
| 74 | + int b=editdistance(s,t.substr(1)); |
| 75 | + int c=editdistance(s.substr(1),t.substr(1)); |
| 76 | + return min(a,min(b,c))+1; |
| 77 | + } |
| 78 | +} |
| 79 | +int main(){ |
| 80 | + string s,t; |
| 81 | + cin>>s>>t; |
| 82 | + cout<<editdistance_dp(s,t)<<endl; |
| 83 | + cout<<editdistance_mem(s,t)<<endl; |
| 84 | + cout<<editdistance(s,t)<<endl; |
| 85 | +} |
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