题目链接 LeetCode 135

错误的代码：

class Solution {
public:
    vector<int> f;
    vector<int> w;
    int n;

    int candy(vector<int>& ratings) {
        n = ratings.size();
        w = ratings;
        f.resize(n, -1);

        int res = 0;
        for (int i = 0; i < n; i ++ ) res += dp(i);

        return res;
    }

    int dp(int x) {
        if (f[x] != -1) return f[x];
        f[x] = 1;
        if (x && w[x - 1] < w[x]) f[x] = max(f[x], dp(x - 1) + 1);
        if (x<=w.size()-2&& w[x + 1] < w[x]) f[x] = max(f[x], dp(x + 1) + 1);
        return f[x];
    }
};

但如果将

if (x<=w.size()-2&& w[x + 1] < w[x]) f[x] = max(f[x], dp(x + 1) + 1);

更改为

if (x <=n-2 && w[x + 1] < w[x]) f[x] = max(f[x], dp(x + 1) + 1);

便可以AC

 ListNode *findFirstCommonNode(ListNode *headA, ListNode *headB) {
        auto p1 = headA, p2 = headB;
        while (p1 != p2)
        {
            if (p1) p1 = p1->next;
            else p1 = headB;
            if (p2) p2 = p2->next;
            else p2 = headA;
        }
        return p1;
    }

 ListNode *findFirstCommonNode(ListNode *headA, ListNode *headB) {
        auto p1 = headA, p2 = headB;
        while (p1 != p2)
        {
            if (p1) p1 = p1->next;
            else p1 = headB;
            if (p2) p2 = p2->next;
            else p2 = headA;
        }
        return p1;
    }

 ListNode *findFirstCommonNode(ListNode *headA, ListNode *headB) {
        auto p1 = headA, p2 = headB;
        while (p1 != p2)
        {
            if (p1) p1 = p1->next;
            else p1 = headB;
            if (p2) p2 = p2->next;
            else p2 = headA;
        }
        return p1;
    }

 ListNode *findFirstCommonNode(ListNode *headA, ListNode *headB) {
        auto p1 = headA, p2 = headB;
        while (p1 != p2)
        {
            if (p1) p1 = p1->next;
            else p1 = headB;
            if (p2) p2 = p2->next;
            else p2 = headA;
        }
        return p1;
    }

 ListNode *findFirstCommonNode(ListNode *headA, ListNode *headB) {
        auto p1 = headA, p2 = headB;
        while (p1 != p2)
        {
            if (p1) p1 = p1->next;
            else p1 = headB;
            if (p2) p2 = p2->next;
            else p2 = headA;
        }
        return p1;
    }

 ListNode *findFirstCommonNode(ListNode *headA, ListNode *headB) {
        auto p1 = headA, p2 = headB;
        while (p1 != p2)
        {
            if (p1) p1 = p1->next;
            else p1 = headB;
            if (p2) p2 = p2->next;
            else p2 = headA;
        }
        return p1;
    }

 ListNode *findFirstCommonNode(ListNode *headA, ListNode *headB) {
        auto p1 = headA, p2 = headB;
        while (p1 != p2)
        {
            if (p1) p1 = p1->next;
            else p1 = headB;
            if (p2) p2 = p2->next;
            else p2 = headA;
        }
        return p1;
    }

 ListNode *findFirstCommonNode(ListNode *headA, ListNode *headB) {
        auto p1 = headA, p2 = headB;
        while (p1 != p2)
        {
            if (p1) p1 = p1->next;
            else p1 = headB;
            if (p2) p2 = p2->next;
            else p2 = headA;
        }
        return p1;
    }

 ListNode *findFirstCommonNode(ListNode *headA, ListNode *headB) {
        auto p1 = headA, p2 = headB;
        while (p1 != p2)
        {
            if (p1) p1 = p1->next;
            else p1 = headB;
            if (p2) p2 = p2->next;
            else p2 = headA;
        }
        return p1;
    }