Partitioning by Palindromes UVA

题目：题目链接

思路：预处理出l到r为回文串的子串，然后如果j到i为回文串，dp[i] = min(dp[i], dp[j] + 1)

AC代码：

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <string>
#include <set>
#include <map>
#include <list>
#include <unordered_set>
#include <unordered_map>
#include <cmath>

#define FRER() freopen("in.txt", "r", stdin)
#define FREW() freopen("out.txt", "w", stdout)
#define INF 0x3f3f3f3f

using namespace std;

const int maxn = 1000 + 5;

int n, len, l, r;
char str[maxn];

bool check[maxn][maxn];
int dp[maxn];

int main()
{
    //FRER();
    scanf("%d", &n);
    while(n--) {
        scanf("%s", str);
        len = strlen(str);
        memset(check, 0, sizeof(check));

        for(int i = 0; i < len; ++i) {
            l = r = i;
            while(l >= 0 && r < len) {
                if(str[l] == str[r]) {
                    check[l + 1][r + 1] = 1;
                    --l; ++r;
                }
                else break;
            }
            l = i;
            r = i + 1;
            
            while(l >= 0 && r < len) {
                if(str[l] == str[r]) {
                    check[l + 1][r + 1] = 1;
                    --l; ++r;
                }
                else break;
            }
        }

        memset(dp, 0, sizeof(dp));
        for(int i = 1; i <= len; ++i) {
            dp[i] = dp[i - 1] + 1;
            for(int j = 1; j < i; ++j) {
                if(check[j][i])
                    dp[i] = min(dp[i], dp[j - 1] + 1);
            }
        }

        printf("%d
", dp[len]);
    }
    return 0;
}