P2400 秘密文件 [区间DP] [字符串]

传送门

f[l][r] 表示 l到r的最小长度

要么由左右两边合并 , 要么自己做一串

#include<bits/stdc++.h>
#define N 105
#define inf 0x3fffffff
using namespace std;
string s,a[N][N]; int n,f[N][N];
int main(){
	memset(f,127,sizeof(f));
	cin>>s; n = s.length();
	for(int i=0;i<n;i++) f[i][i] = 1 , a[i][i] = s[i];
	for(int len=2;len<=n;len++){
		for(int l=0;l<n;l++){
			int r = l + len - 1;
			int ans = inf, pos;
			if(r>n-1) break;
			for(int k=l;k<r;k++)
				if(f[l][k] + f[k+1][r] < ans) 
					ans = f[l][k] + f[k+1][r] , pos = k;
			a[l][r] = a[l][pos] + a[pos+1][r];
			int same = 0;
			for(int k=1;k<=len/2;k++){
				if(len%k) continue; int flag=0;
				for(int i=l;i<=r;i++){
					if(i+k > r) break;
					if(s[i] != s[i+k]){flag = 1; break;}
				} if(!flag){same = k; break;}
			}
			if(same){
				char now[N]; int num = len / same , v[10] , tot=0;
				memset(v,0,sizeof(v));  memset(now,0,sizeof(now));
				while(num) v[++tot] = num%10 , num /= 10;
				if(tot + same + 2 < ans){
					for(int i=1;i<=tot;i++) now[tot-i] = v[i] + '0';
					tot--; now[++tot] = '(';
					for(int i=l;i<l+same;i++) now[++tot] = s[i];
					now[++tot] = ')';  a[l][r] = now;
				}
			}
			f[l][r] = ans;
		}
	}cout<<a[0][n-1]; return 0;
}