标签：des style http color os io strong for
Description
| 0 s, 1 s and ? Marks |
Given a string consisting of 0, 1 and ? only, change all the ? to 0/1, so that the size of the largest group is minimized. A group is a substring that contains either all zeros or all ones.
Consider the following example:
0 1 1 ? 0 1 0 ? ? ?
We can replace the question marks (?) to get
0 1 1 0 0 1 0 1 0 0
The groups are (0) (1 1) (0 0) (1) (0) (1) (0 0) and the corresponding sizes are 1, 2, 2, 1, 1, 1, 2. That means the above replacement would give us a maximum group size of 2. In fact, of all the 24 possible replacements, we won‘t get any maximum group size that is smaller than 2.
Input
The first line of input is an integer T (T
5000) that indicates
the number of test cases. Each case is a line consisting of a string that contains
0, 1 and ? only. The length of the string will be in the range [1,1000].
Output
Sample Input
4 011?010??? ??? 000111 00000000000000
Sample Output
Case 1: 2 Case 2: 1 Case 3: 3 Case 4: 14
题意：给定一个带问号的01串，把每个问号替换成0或1，让最长的“连续的相同数字串”尽量短
思路：最大的最小采用二分，至于判断的时候，每个位置要么是0要么是1，根据情况判断
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int maxn = 1005;
int dp[maxn][2];
char str[maxn];
int n;
int check(int len) {
dp[0][0] = dp[0][1] = 0;
for (int i = 1; i <= n; i++) {
dp[i][0] = dp[i][1] = -1;
if (str[i] != '0') {
if (dp[i-1][0] >= 0)
dp[i][1] = 1;
if (dp[i-1][1] >= 0 && dp[i-1][1]+1 <= len && dp[i][1] == -1)
dp[i][1] = dp[i-1][1] + 1;
}
if (str[i] != '1') {
if (dp[i-1][1] >= 0)
dp[i][0] = 1;
if (dp[i-1][0] >= 0 && dp[i-1][0]+1 <= len && dp[i][0] == -1)
dp[i][0] = dp[i-1][0] + 1;
}
if (dp[i][1] == -1 && dp[i][0] == -1)
return 0;
}
return 1;
}
int main() {
int t, cas = 1;
scanf("%d", &t);
while (t--) {
scanf("%s", str+1);
n = strlen(str+1);
int l = 1, r = n;
while (l <= r) {
int m = l + r >> 1;
if (check(m))
r = m-1;
else l = m + 1;
}
printf("Case %d: %d\n", cas++, l);
}
return 0;
}UVA - 11920 0 s, 1 s and ? Marks,布布扣,bubuko.com
UVA - 11920 0 s, 1 s and ? Marks
标签：des style http color os io strong for
原文地址：http://blog.csdn.net/u011345136/article/details/38490353
