LIS (DP)_代码

 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 int max(int a, int b);
 int main()
 {
     int n;
     scanf("%d", &n);
     int i;
     //arr stores data
     int arr[];
     //path stores LIS result
     int path[];
     //init
     memset(arr, 0x00, sizeof(arr));
     memset(path, 0x00, sizeof(path));
     //input test data
     for (i = ; i < n; i++) {
         scanf("%d", &arr[i]);
     }

     for (i = ; i < n; ++i) {
         if(i==){
             path[i] = ;
         }
         else {
             //Before arr[i],path[0~i-1] has been found,
             //if(arr[i-1] <= arr[i]) path[i] = path[i-1]+1;
             if(arr[i-] <= arr[i]){
                 path[i] = path[i-]+;
             }else {
                 //or else compare arr[i] with arr[i-1~0] until arr[x] <= arr[i]
                 int idx;
                 for(idx=i-;idx>=;--idx){
                     if(arr[idx]<=arr[i]){
                         path[i] = path[idx]+;
                         break;
                     }else {
                         path[i] = ;
                         continue;
                     }
                 }

             }
         }
     }

     int max = ;
     for (i = ; i < n; i++) {
         if (max < path[i]) {
             max = path[i];
         }
     }
     printf("%d\n", max);
     return ;
 }
 /*
 6
 5 3 4 8 6 7
  */
 int max(int a, int b)
 {
     return ((a >= b) ? a : b);
 }