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[101];
    //path stores LIS result
    int path[101];
    //init
    memset(arr, 0x00, sizeof(arr));
    memset(path, 0x00, sizeof(path));
    //input test data
    for (i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }

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

            }
        }
    }

    int max = 0;
    for (i = 0; i < n; i++) {
        if (max < path[i]) {
            max = path[i];
        }
    }
    printf("%d
", max);
    return 0;
}
/*
6
5 3 4 8 6 7
 */
int max(int a, int b)
{
    return ((a >= b) ? a : b);
}