CF607B Zuma(区间dp)

题意

题目链接

Sol

裸的区间dp，转移的时候判一下两个字符是否相等即可

#include<bits/stdc++.h>

#define Pair pair<int, int>

#define MP(x, y) make_pair(x, y)

#define fi first

#define se second

#define LL long long

#define ull unsigned long long

#define Fin(x) {freopen(#x".in","r",stdin);}

#define Fout(x) {freopen(#x".out","w",stdout);}

using namespace std;

const int MAXN = 5001, mod = 1e9 + 7, INF = 1e9 + 10;

const double eps = 1e-9;

template <typename A, typename B> inline bool chmin(A &a, B b){if(a > b) {a = b; return 1;} return 0;}

template <typename A, typename B> inline bool chmax(A &a, B b){if(a < b) {a = b; return 1;} return 0;}

template <typename A, typename B> inline LL add(A x, B y) {if(x + y < 0) return x + y + mod; return x + y >= mod ? x + y - mod : x + y;}

template <typename A, typename B> inline void add2(A &x, B y) {if(x + y < 0) x = x + y + mod; else x = (x + y >= mod ? x + y - mod : x + y);}

template <typename A, typename B> inline LL mul(A x, B y) {return 1ll * x * y % mod;}

template <typename A, typename B> inline void mul2(A &x, B y) {x = (1ll * x * y % mod + mod) % mod;}

template <typename A> inline void debug(A a){cout << a << '\n';}

template <typename A> inline LL sqr(A x){return 1ll * x * x;}

inline int read() {

    char c = getchar(); int x = 0, f = 1;

    while(c < '0' || c > '9') {if(c == '-') f = -1; c = getchar();}

    while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();

    return x * f;

}

int N, a[MAXN], f[MAXN][MAXN];

signed main() {

    N = read();

    for(int i = 1; i <= N; i++) a[i] = read(), f[i][i] = 1;

    for(int len = 2; len <= N; len++) {

        for(int l = 1; l + len - 1 <= N; l++) {

            int r = l + len - 1;

            f[l][r] = r - l + 1;

            for(int k = l; k < r; k++) chmin(f[l][r], f[l][k] + f[k + 1][r]);

            if(a[l] == a[r]) chmin(f[l][r], f[l + 1][r - 1] + (r - l == 1));

        }

    }

    cout << f[1][N];

    return 0;

}