简单dp水题

#include <bits/stdc++.h>
using namespace std;
#define limit (100 + 5)//防止溢出
#define INF 0x3f3f3f3f
#define inf 0x3f3f3f3f3f
#define lowbit(i) i&(-i)//一步两步
#define EPS 1e-6
#define FASTIO  ios::sync_with_stdio(false);cin.tie(0);
#define ff(a) printf("%d\n",a );
#define pi(a,b) pair<a,b>
#define rep(i, a, b) for(ll i = a; i <= b ; ++i)
#define per(i, a, b) for(ll i = b ; i >= a  ; --i)
#define MOD 998244353
#define traverse(u) for(int i = head[u]; ~i ; i = edge[i].next)
#define FOPEN freopen("C:\\Users\\tiany\\CLionProjects\\acm_01\\data.txt", "rt", stdin)
#define FOUT freopen("C:\\Users\\tiany\\CLionProjects\\acm_01\\dabiao.txt", "wt", stdout)
#define debug(x) cout<<x<<endl
typedef long long ll;
typedef unsigned long long ull;
inline ll read(){
    ll sign = 1, x = 0;char s = getchar();
    while(s > '9' || s < '0' ){if(s == '-')sign = -1;s = getchar();}
    while(s >= '0' && s <= '9'){x = (x << 3) + (x << 1) + s - '0';s = getchar();}
    return x * sign;
}//快读
void write(ll x){
    if(x < 0) putchar('-'),x = -x;
    if(x / 10) write(x / 10);
    putchar(x % 10 + '0');
}
int n,m;
const int mod = 1000007;
int dp[limit][limit];//总数是多少
int a[limit];
int main() {
#ifdef LOCAL
    FOPEN;
#endif
    n = read(),m = read();
    rep(i,1,n){
        a[i] = read();
    }
    dp[0][0] = 1;
    rep(i,1,n){
        rep(j,0,a[i]){
            rep(k,0,m){
                if(k - j < 0)continue;
                dp[i][k] += dp[i - 1][k - j];
                dp[i][k] %= mod;
            }
        }
    }
    ll ans = dp[n][m] % mod;
    write(ans);
    return 0;
}

最近事情也挺多的,刷题也基本停止了。今天才开始继续刷的。老妈说我这几天做了好几次噩梦,都是睡觉的时候突然惊呼“太难了!”。

希望有时间能够准备gre,orz,都十月了!搞完手头的就去gre,下周开始准备,周三之前买书(flag++)。

祝WeepingDemon和Oak_limy以及所有初赛er rp++

大学课业太多单身三年了,求求这些教授有点人性批点时间给我谈个恋爱吧orz

毕~

 

posted @ 2020-10-10 21:30  tiany7  阅读(95)  评论(0编辑  收藏  举报