Codeforces 1148 E

E - Earth Wind and Fire

思路：

栈模拟

代码：

#pragma GCC optimize(2)
#pragma GCC optimize(3)
#pragma GCC optimize(4)
#include<bits/stdc++.h>
using namespace std;
#define y1 y11
#define fi first
#define se second
#define pi acos(-1.0)
#define LL long long
//#define mp make_pair
#define pb emplace_back
#define ls rt<<1, l, m
#define rs rt<<1|1, m+1, r
#define ULL unsigned LL
#define pll pair<LL, LL>
#define pli pair<LL, int>
#define pii pair<int, int>
#define piii pair<int, pii>
#define puu pair<ULL, ULL>
#define pdd pair<long double, long double>
#define mem(a, b) memset(a, b, sizeof(a))
#define fio ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define fopen freopen("in.txt", "r", stdin);freopen("out.txt", "w", stout);
//head

int main() {
    int n;
    scanf("%d", &n);
    vector<pii> a(n);
    vector<int> b(n);
    for (int i = 0; i < n; ++i) scanf("%d", &a[i].fi), a[i].se = i;
    for (int i = 0; i < n; ++i) scanf("%d", &b[i]);
    sort(a.begin(), a.end());
    sort(b.begin(), b.end());
    vector<tuple<int, int,int>> res;
    vector<pii> st;
    for (int i = 0; i < n; ++i) {
        int d = b[i]-a[i].fi;
        if(d == 0) continue;
        if(d > 0) {
            st.pb(d, a[i].se);
        }
        else {
            while(d < 0) {
                if(st.empty()) return 0*puts("NO");
                int dd = min(st.back().fi, -d);
                d += dd;
                st.back().fi -= dd;
                res.pb(st.back().se, a[i].se, dd);
                if(st.back().fi == 0) st.pop_back();
            }
        }
    }
    if(!st.empty()) return 0*puts("NO");
    printf("YES
%d
", (int)res.size());
    for (auto p : res) printf("%d %d %d
", get<0>(p)+1, get<1>(p)+1, get<2>(p));
    return 0;
}