【HDOJ】1231 最大公共子序列

经典DP。

#include <stdio.h>

#define MAXNUM 10005

int array[MAXNUM];
int dp[MAXNUM];

int main() {
    int n, beg, end, max;
    int i, k;

    dp[0] = 0;
    while (scanf("%d", &n)!=EOF && n) {
        k = 0;
        for (i=1; i<=n; ++i) {
            scanf("%d", &array[i]);
            if (array[i] >= 0)
                k = 1;
        }
        if (k == 0) {
            printf("0 %d %d\n", array[1], array[n]);
            continue;
        }
        max = -1;
        for (i=1; i<=n; ++i) {
            if (dp[i-1]+array[i] < 0) {
                dp[i] = 0;
            } else {
                dp[i] = dp[i-1]+array[i];
                if (dp[i] > max) {
                    max = dp[i];
                    end = i;
                }
            }
        }
        k = end-1;
        while (k) {
            if (dp[k] == 0)
                break;
            k--;
        }
        beg = k+1;
        printf("%d %d %d\n", max, array[beg], array[end]);
    }

    return 0;
}