为什么我的代码，在 $calc$ 计算当前函数值的时候将 $k-1$ 就全 $WA$，但是改成一开始将 $line.b-line.k$ 就过了啊。

#include<bits/stdc++.h>

#define ll long long
#define LF putchar('\n')
#define SP putchar(' ')
#define pii pair<int,int>

template <typename T>
void read(T& x) {
	x = 0;
	char ch = getchar();
	long long f = 1;
	while (!isdigit(ch)) {
		if (ch == '-')
			f *= -1;
		ch = getchar();
	}
	while (isdigit(ch)) {
		x = (x << 3) + (x << 1) + (ch ^ 48);
		ch = getchar();
	}
	x *= f;
}
template <typename T, typename... Args>
void read(T& first, Args&... args) {
	read(first);
	read(args...);
}
template <typename T>
void write(T arg) {
	T x = arg;
	if (x < 0) {
		putchar('-');
		x = -x;
	}
	if (x > 9) {
		write(x / 10);
	}
	putchar(x % 10 + '0');
}

template <typename T, typename... Ts>
void write(T arg, Ts... args) {
	write(arg);
	if (sizeof...(args) != 0) {
		putchar(' ');
		write(args...);
	}
}
const int N = 5e4 + 10;
const int M = 1e5+10;
const int INF = 0x3f3f3f3f;
using namespace std;
const double eps = 1e-8;
#define int long long
int n;
struct node {
	double k, b;
} line[M];
int tot;

double calc(int id, double pos) {
	if(id == -1) return -1e9;
	if (!id) return -1e9;
	return line[id].b + (line[id].k)*pos;
}
int tr[N<<3];
//void update(int rt, int l, int r, int id) {
//
//	int mid = l + r >> 1;
//	if (calc(id, mid) > calc(tr[rt], mid) || (fabs(calc(id, mid) - calc(tr[rt], mid)) < eps && id < tr[rt])) swap(tr[rt], id);
//	if (l == r) return;
//	update(rt << 1, l, mid, id);
//	update(rt << 1 | 1, mid + 1, r, id);
//}

void update(int rt, int l, int r, int L, int R, int id) {
	int mid = l + r >> 1;
//	cout<<1;
	if (L <= l && R >= r) {
		if ((calc(id, mid) > calc(tr[rt], mid)) || (fabs(calc(id, mid) - calc(tr[rt], mid)) < eps && id < tr[rt]))
			swap(id, tr[rt]);
		if (l == r) return;
		if(line[id].k<line[tr[rt]].k) update(rt<<1,l,mid,L,R,id);
		else update(rt<<1|1,mid+1,r,L,R,id);
		return;
	}
	if(L<=mid) update(rt<<1,l,mid,L,R,id);
	if(R>mid) update(rt<<1|1,mid+1,r,L,R,id);
}

int ans;

double query(int rt, int l, int r, int pos) {
//	write(1);
//	cout<<l<<" "<<r<<endl;
	if(l == r){
//		cout<<rt<<endl;
		return calc(tr[rt],pos);
	}
	int mid = l+r>>1;
	if(pos<=mid) return max(calc(tr[rt],pos),query(rt<<1,l,mid,pos));
	else return max(calc(tr[rt],pos),query(rt<<1|1,mid+1,r,pos));
}



signed main() {
	read(n);
	for (int i = 1; i <= n; i++) {
		char op[10];
		scanf("%s", op);
		if (op[0] == 'P') {
			++tot;
			scanf("%lf%lf",&line[tot].b,&line[tot].k);
			line[tot].b -= line[tot].k;
			update(1,1,N,1,N,tot);
		} else {
			int t;
			read(t);
			ans = query(1,1,N,t)/100;
			write(max(0ll,ans));
			LF;
//			ans = -1;
//			query(1,1,N,t);
//			if(ans == -1) write(0);
//			else{
//				int res = calc(ans,t)/100;
//				write(res);
//			}
//			LF;
		}
	}



	return 0;
}