Brackets Sequence POJ - 1141 （区间dp）

 1 #include<cstdio>
 2 #include<algorithm>
 3 #include<string>
 4 #include<iostream>
 5 #include <cstdlib>
 6 #include<cstring>
 7 using namespace std;
 8 const int maxn=110;
 9 const int inf=0x3f3f3f3f;
10 int dp[maxn][maxn],flag[maxn][maxn];
11 char s[maxn];
12 
13 void print(int l,int r){
14     if(l>r) return ;
15     if(l==r){
16         if(s[l]==‘(‘||s[l]==‘)‘) printf("()");
17         else printf("[]");
18         return ;
19     }
20     if(flag[l][r]==-1){
21         putchar(s[l]);
22         print(l+1,r-1);
23         putchar(s[r]);
24     }else {
25         print(l,flag[l][r]);
26         print(flag[l][r]+1,r);
27     }
28 }
29 int main(){
30     while(gets(s)){
31         memset(dp,0,sizeof(dp));
32         int len=strlen(s);
33         for(int i=0;i<len;i++) dp[i][i]=1;
34         for(int i=len-2;i>=0;i--)
35             for(int j=i+1;j<len;j++){
36             dp[i][j]=inf;
37             if(s[i]==‘(‘&&s[j]==‘)‘||s[i]==‘[‘&&s[j]==‘]‘)
38             if(dp[i][j]>dp[i+1][j-1]){
39                 dp[i][j]=dp[i+1][j-1];
40                 flag[i][j]=-1;
41             }
42             for(int k=i;k<j;k++)
43                 if(dp[i][j]>dp[i][k]+dp[k+1][j]){
44                     dp[i][j]=dp[i][k]+dp[k+1][j];
45                     flag[i][j]=k;
46                 }
47         }
48         print(0,len-1);
49         puts("");
50     }
51 }

 1 #include<cstdio>
 2 #include<algorithm>
 3 #include<string>
 4 #include<iostream>
 5 #include <cstdlib>
 6 #include<cstring>
 7 using namespace std;
 8 const int maxn=110;
 9 const int inf=0x3f3f3f3f;
10 int dp[maxn][maxn],flag[maxn][maxn];
11 char s[maxn];
12 
13 void print(int l,int r){
14     if(l>r) return ;
15     if(l==r){
16         if(s[l]==‘(‘||s[l]==‘)‘) printf("()");
17         else printf("[]");
18         return ;
19     }
20     if(flag[l][r]==-1){
21         putchar(s[l]);
22         print(l+1,r-1);
23         putchar(s[r]);
24     }else {
25         print(l,flag[l][r]);
26         print(flag[l][r]+1,r);
27     }
28 }
29 int main(){
30     while(gets(s)){
31         memset(dp,0,sizeof(dp));
32         int len=strlen(s);
33         for(int i=0;i<len;i++) dp[i][i]=1;
34         for(int k=1;k<len;k++){
35             for(int i=0;i+k<len;i++){
36                 int j=i+k;
37                 dp[i][j]=inf;
38                 if(s[i]==‘(‘&&s[j]==‘)‘||s[i]==‘[‘&&s[j]==‘]‘)
39                 if(dp[i][j]>dp[i+1][j-1]){
40                     dp[i][j]=dp[i+1][j-1];
41                     flag[i][j]=-1;
42                 }
43                 for(int m=i;m<j;m++){
44                     if(dp[i][j]>dp[i][m]+dp[m+1][j]){
45                         dp[i][j]=dp[i][m]+dp[m+1][j];
46                         flag[i][j]=m;
47                     }
48                 }
49             }
50         }
51         print(0,len-1);
52         puts("");
53     }
54 }