codeforces B - Collecting Game

分析

  • a i a_i ai 小的一定对 a n s i ans_i ansi 有贡献(应该加上)。加上之后 s c o r e score score 变大,在 s c o r e score score 变大的过程中可能会有更多的 a j a_j aj 小于 s c o r e score score
  • 很容易想到排序,排序之后当前 s c o r e score score 就是 ∑ j = 1 i a j \sum\limits_{j = 1}^ia_j j=1iaj ,设 d p i dp_i dpi 表示当前 i i i 往右能覆盖的最多个数。双指针找到最大范围 r r r ,那么 a n s i = r − i + d p i ans_i = r - i + dp_i ansi=ri+dpi

Think Twice, Code Once

signed main() {
 
    int T = 1;
    T = read();
    while (T--) {
        int n = read();
        vector<pii> a(n + 1);
        int sum = 0;
        for (int i = 1; i <= n; ++i) {
            a[i].first = read(), a[i].second = i;
            sum += a[i].first;
        }
        sort(a.begin() + 1, a.end());
        int r = n;
        vector<int> dp(n + 1), ans(n + 1);
        ans[a[n].second] = n - 1;
        for (int i = n - 1; i >= 1; --i) {
            sum -= a[i + 1].first;
            while (a[r].first > sum) --r;
            dp[i] += r - i + dp[r];
            ans[a[i].second] = i - 1 + dp[i];
        }
        for (int i = 1; i <= n; ++i) writesp(ans[i]);
        puts("");
    }
    return 0;
}

你可能感兴趣的:(codeforces题解,dp,算法,c++,思维,paixu,dp)