Cf273 (D2) d DP

[Question ]:

Given n green bricks and M red bricks, build as high as possible, each line can only use one color.

How many heap methods are available.

[Knowledge point ]:

DP scrolling Array

[Question ]:

In the code, DP [I] indicates the type of accumulation corresponding to the I red block.

    REP(i, h)        for(int j = N - i; j >= 0; j--)            dp[i + j] = (dp[i + j] + dp[j]) % MOD;

The first layer of the cycle indicates that the length of the building blocks is increased from small to large, and the second layer is updated in a rolling manner.

[Code ]:

#include <map>#include <set>#include <cmath>#include <ctime>#include <queue>#include <stack>#include <cstdio>#include <string>#include <vector>#include <cstring>#include <sstream>#include <iostream>#include <algorithm>#include <bitset>#include <climits>using namespace std;#define wh while#define inf (int)(~0u/2)#define FOR(i, n) for(int i = 0; i < n; i++)#define FOR1(i, n) for(int i = 1; i < n; i++)#define FOR2(i, n) for(int i = 0; i <= n; i++)#define REP(i,n) for(int i = 1; i <= n; i++)#define FORI(it,n) for(typeof(n.begin()) it = n.begin(); it != n.end(); it++)#define sf scanf#define pf printf#define frs first#define sec second#define psh push_back#define mkp make_pair#define PB(x) push_back(x)#define MP(x, y) make_pair(x, y)#define clr(abc,z) memset(abc,z,sizeof(abc))#define lt(v) v << 1#define rt(v) v << 1 | 1//#define mid ((l + r) >> 1)#define lson l, mid, v << 1#define rson mid + 1, r, v << 1 | 1#define fre freopen("1.txt", "r", stdin)typedef long long LL;typedef long double LD;int N, M;const int maxn = 2e5 + 100;const int MOD = 1000000007;int dp[maxn];int main() {    sf("%d%d", &N, &M);    int h; for(h = 1; h * (h + 1) / 2 <= (N + M); h++); h--;    dp[0] = 1;    REP(i, h)        for(int j = N - i; j >= 0; j--)            dp[i + j] = (dp[i + j] + dp[j]) % MOD;    h = (h + 1) * h / 2; int ans; ans = 0;    for(int j = 0; j <= N; j++)        if(h - j <= M) ans = (ans + dp[j]) % MOD;    pf("%d\n", ans);}

 

Cf273 (D2) d DP