hdu1025 Constructing Roads In JGShining's Kingdom（最长递增公共子序列二分法）

#include <stdio.h>
#include <string.h>
#include <cstdio>
#include <algorithm>

using namespace std;

const int N = 500005;
const int INF = 1<<27;

struct CIT
{
int r;
int p;
}cit
;

bool cmp(CIT a, CIT b)
{
if(a.r < b.r)
return true;
else
return false;
}

int main()
{
//   freopen("in.txt", "r", stdin);
int T, n, i, k, Case = 1, ans;
int dp
;
while(~scanf("%d", &n))
{
for(int i = 1; i <= n; i ++)
{
scanf("%d%d", &cit[i].p, &cit[i].r);
dp[i] = INF;
}
sort(cit + 1, cit + n + 1, cmp);
ans = 0;
for(i = 1; i <= n; i ++)
{
k = lower_bound(dp + 1, dp + n + 1, cit[i].p) - dp;
//      printf("%d ", k);
ans = max(ans, k);
//       printf("%d ", ans);
dp[k] = cit[i].p;
//      printf("%d\n", dp[k]);
}
if(ans == 1) printf("Case %d:\nMy king, at most %d road can be built.\n\n", Case ++, ans);
else printf("Case %d:\nMy king, at most %d roads can be built.\n\n", Case ++, ans);
}
return 0;
}