[SCOI 2003] 字符串折叠

[题目链接]

         https://www.lydsy.com/JudgeOnline/problem.php?id=1090

[算法]

         区间DP

[代码]

        

#include<bits/stdc++.h>
using namespace std;
#define MAXN 110

int len;
int f[MAXN][MAXN];
char s[MAXN];

inline int calc(int x)
{
        int ret = 0;
        while (x)
        {
                ret++;
                x /= 10;
        }
        return ret;
}
inline bool check(int l,int r,int pl,int pr)
{
        int i;
        if ((r - l + 1) % (pr - pl + 1) != 0) return false;
        for (i = l; i <= r; i++)
        {
                if (s[i] != s[(i - l) % (pr - pl + 1) + pl])
                        return false;
        }
        return true;
}
inline int dp(int l,int r)
{
        int i;
        if (l == r) return f[l][r] = 1;
        if (f[l][r] != -1) return f[l][r];
        f[l][r] = r - l + 1;
        for (i = l; i < r; i++)
        {
                f[l][r] = min(f[l][r],dp(l,i) + dp(i + 1,r));
                if (check(i + 1,r,l,i))
                        f[l][r] = min(f[l][r],dp(l,i) + calc((r - i) / (i - l + 1) + 1) + 2);
        }
        return f[l][r];
} 
int main() 
{
        
        scanf("%s",s + 1);
        len = strlen(s + 1);
        memset(f,255,sizeof(f));
        printf("%d
",dp(1,len));
        
        return 0;
    
}