CF-1023-C. Maximum Subarray Sum · znzryb

## 思路讲解

赛时差一点想到AC，主要是needVal为负数的情况没有想到（减着减着变负数了）

其实只改一个数就行，其他数全部赋为-INF。

## AC代码

[https://codeforces.com/contest/2107/submission/318579760](https://codeforces.com/contest/2107/submission/318579760)



::: 源代码

```cpp
// Problem: C. Maximum Subarray Sum
// Contest: Codeforces - Codeforces Round 1023 (Div. 2)
// URL: https://codeforces.com/contest/2107/problem/C
// Memory Limit: 256 MB
// Time Limit: 2000 ms
// by znzryb
// 
// Powered by CP Editor (https://cpeditor.org)

#include <bits/stdc++.h>
#define all(x) x.begin(),x.end()
#define CLR(i,a) memset(i,a,sizeof(i))
#define fi first
#define se second
#define pb push_back
#define SZ(a) ((int) a.size())
#define FOR(i, a, b) for (int i = (a); i <= (b); ++i)
#define ROF(i, a, b) for (int i = (a); i >= (b); --i)

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef __int128 i128;
typedef pair<ll,ll> pll;
typedef array<ll,3> arr;
typedef double DB;
typedef pair<DB,DB> pdd;
typedef pair<ll,bool> plb;
constexpr ll MAXN=static_cast<ll>(1e6)+10,INF=static_cast<ll>(1e18)-3;
constexpr ll mod=static_cast<ll>(1e9)+7;
constexpr double eps=1e-8;

ll N,M,K,T,A[MAXN];
char S[MAXN];
// ll preA[MAXN];
ll mxA[MAXN],smxA[MAXN];//sumA[MAXN];

inline void solve(){
	cin>>N>>K;
	FOR(i,0,N+5){
		S[i]='0';
		A[i]=0;
		smxA[i]=0;
		mxA[i]=0;
		// sumA[i]=0;
	}
	FOR(i,1,N){
		cin>>S[i];
	}
	ll pos=0;
	FOR(i,1,N){
		cin>>A[i];
		if(S[i]=='0') A[i]=-INF,pos=i;
		// sumA[i]=sumA[i-1]+A[i];
	}
	// preA[0]=0;
	ll maxA=-INF;
	FOR(i,1,N){
		if(S[i]=='1'){
			mxA[i]=mxA[i-1]+A[i];
			maxA=max(maxA,mxA[i]);
			if(mxA[i]<0){
				mxA[i]=0;
			}
		}else{
			mxA[i]=0;
		}
	}
	smxA[N+1]=0;
	ROF(i,N,1){
		if(S[i]=='1'){
			smxA[i]=smxA[i+1]+A[i];
			maxA=max(maxA,smxA[i]);
			if(smxA[i]<0){
				smxA[i]=0;
			}
		}else{
			smxA[i]=0;
		}
	}
	if(maxA>K){
		cout<<"No\n";
		return;
	}else if(maxA==K){
		cout<<"Yes\n";
		FOR(i,1,N){
			if(S[i]=='0') A[i]=-INF;
			cout<<A[i]<<" ";
		}
		cout<<"\n";
		return;
	}
	A[pos]=K-smxA[pos+1]-mxA[pos-1];
	ll check=-INF;
	mxA[0]=0;
	FOR(i,1,N){
		mxA[i]=mxA[i-1]+A[i];
		check=max(check,mxA[i]);
		if(mxA[i]<0){
			mxA[i]=0;
		}
	}
#ifdef LOCAL
    cerr << "T:"<<T << '\n';
    cerr<<"check:"<<check<<" K:"<<K<<"\n";
    FOR(i,1,N){
    	cerr<<A[i]<<" ";
    }
    cerr<<"\n";
#endif
	if(check==K){
		cout<<"Yes\n";
		FOR(i,1,N){
			cout<<A[i]<<" ";
		}
		cout<<"\n";
	}else{
		cout<<"No\n";
	}
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);cout.tie(0);
	cin>>T;
	while(T--){
		solve();
	}
	// solve();
	return 0;
}
/*
AC
https://codeforces.com/contest/2107/submission/318579760
*/
```


:::


## 心路历程（WA，TLE，MLE……）