sdut 1451 括号东东 DP
http://acm.sdut.edu.cn/sdutoj/problem.php?action=showproblem&problemid=1451
题意:中文.....
思路:
pku有一道题,经典的括号匹配(区间DP)题目,那道题目是求的最长满足条件的子串的长度,那里的子串与这里的子串条件不一样。
详细:http://www.cnblogs.com/E-star/archive/2013/01/28/2879385.html
对于这个例子
)((())))(()())
pku的最长子串是12
而这里是6
这里我们是求的连续的满足的子串。
dp[i]表示0到i的最长的满足的连续的子串
则有:
if(str[i - dp[i - 1] - 1] == '(' && str[i] == ')') dp[i] = dp[i - dp[i - 1] - 1] + 2;
if (dp[i - dp[i - 1] - 2])
dp[i] += dp[i - dp[i - 1] - 2]
//#pragma comment(linker,"/STACK:327680000,327680000") #include <iostream> #include <cstdio> #include <cmath> #include <vector> #include <cstring> #include <algorithm> #include <string> #include <set> #include <functional> #include <numeric> #include <sstream> #include <stack> #include <map> #include <queue> #define CL(arr, val) memset(arr, val, sizeof(arr)) #define ll long long #define inf 0x7f7f7f7f #define lc l,m,rt<<1 #define rc m + 1,r,rt<<1|1 #define pi acos(-1.0) #define ll long long #define L(x) (x) << 1 #define R(x) (x) << 1 | 1 #define MID(l, r) (l + r) >> 1 #define Min(x, y) (x) < (y) ? (x) : (y) #define Max(x, y) (x) < (y) ? (y) : (x) #define E(x) (1 << (x)) #define iabs(x) (x) < 0 ? -(x) : (x) #define OUT(x) printf("%I64d\n", x) #define lowbit(x) (x)&(-x) #define Read() freopen("din.txt", "r", stdin) #define Write() freopen("dout.txt", "w", stdout); #define N 1000007 using namespace std; int dp[N]; int ans,num; char str[N]; int n; int main() { // Read(); int i; while (~scanf("%s",str)) { n = strlen(str); CL(dp,0); num = 0; ans = 0; for (i = 1; i < n; ++i) { if (i - dp[i - 1] - 1 >= 0 && str[i - dp[i - 1] - 1] == '(' && str[i] == ')') { dp[i] = dp[i - 1] + 2; if (i - dp[i - 1] - 2 >= 0 && dp[i - dp[i - 1] -2] != 0) { dp[i] += dp[i - dp[i - 1] - 2]; } } if (ans < dp[i]) { ans = dp[i]; num = 1; } else if (ans == dp[i]) num++; } if (ans == 0) printf("0 1\n"); else printf("%d %d\n",ans,num); } return 0; }