HDU 1257 最少拦截系统

题目：http://acm.hdu.edu.cn/showproblem.php?pid=1257

贪心解法：

#include<stdio.h>int a[3005],vist[3005];int main(){int i,n,count,temp,j;while(scanf("%d",&n)!=EOF){for(i=0;i<n;i++){scanf("%d",&a[i]);vist[i] =0;}count = 0;for(i=0;i<n;i++){if(!vist[i]){temp = a[i];count++;vist[i] = 1;for(j=i+1;j<n;j++){if(a[j] <= temp && !vist[j] ){temp = a[j];vist[j]=1;}}}}printf("%d\n",count);}return 0;}

求最长递增序列

#include<stdio.h>int a[3005],dp[3005];int main(){int i,n,res,j;freopen("a.txt","r",stdin);while(scanf("%d",&n)!=EOF){for(i=0;i<n;i++)scanf("%d",&a[i]);res = -1;for(i=0;i<n;i++){dp[i] = 1;for(j=0;j<i;j++)if( a[i] > a[j] && dp[i] < dp[j]+1){dp[i] = dp[j]+1;if ( dp[i] > res)res = dp[i];}}printf("%d\n",res);}return 0;}