HDU 1950 Bridging signals (DP动态规划 + 二分搜索 O(nlogn) )

#include <stdio.h>
#define MAX_POARTS 40000

int numOfTests;
int numOfPorts;
int arrayOfPorts[MAX_POARTS + 1];
//minTail[len]表示在所有长度为len的递增子序列中的终止元素(也就是子序列中的最大值)里面的最小值
int minTail[MAX_POARTS + 1];
//需要更新对应的minTail[lenOfIS]
int lenOfIS;//length of increasing subsequence
int result;//length of longest of increasing subsequence

//用二分搜索的方法返回minTail中port的下标,如果port不在minTail中，返回第一个比port大的元素的下标
int binSearch(int port){
int start = 1;
int end = result;
while (start <= end){
int mid = (start + end) / 2;
if (port < minTail[mid])
end = mid - 1;
else if(port > minTail[mid])
start = mid + 1;
else
return mid；
}
return start;
}

int main(){

scanf("%d", &numOfTests);
int test;
for (test = 1; test <= numOfTests; test++){
scanf("%d", &numOfPorts);
int indexOfPort;
for (indexOfPort = 1; indexOfPort <= numOfPorts; indexOfPort++)
scanf("%d", &arrayOfPorts[indexOfPort]);

result = 1;
minTail[result] = arrayOfPorts[1];
for (indexOfPort = 2; indexOfPort <= numOfPorts; indexOfPort++){
int port = arrayOfPorts[indexOfPort];
lenOfIS = 0;
if (port <= minTail[1])
lenOfIS = 1;
else if (port > minTail[result])
lenOfIS = ++result;
else if (port < minTail[result])
lenOfIS = binSearch(port);
minTail[lenOfIS] = port;
}

printf("%d\n", result);
}

return 0;
}