1 #include <cstdio> 2 #include <iostream> 3 #include <algorithm> 4 #define root 1, 1, n 5 #define ls now << 1, l, mid 6 #define rs now << 1 | 1, mid + 1, r 7  8 const int INF = ~(1 << 31), MAXN = 100001; 9 int n, m, ans;10 int minn[MAXN << 2], add[MAXN << 2];11 12 struct node13 {14     int a, b;15 }p[MAXN];16 17 inline void swap(int &x, int &y)18 {19     x ^= y ^= x ^= y;20 }21 22 inline void push_up(int now)23 {24     minn[now] = std::min(minn[now << 1], minn[now << 1 | 1]);25 }26 27 inline void push_down(int now, int len)28 {29     if(!add[now]) return;30     add[now << 1] += add[now];31     add[now << 1 | 1] += add[now];32     minn[now << 1] += add[now];33     minn[now << 1 | 1] += add[now];34     add[now] = 0;35 }36 37 inline void build(int now, int l, int r)38 {39     if(l == r)40     {41         scanf("%d", &minn[now]);42         return;43     }44     int mid = (l + r) >> 1;45     build(ls);46     build(rs);47     push_up(now);48 }49 50 inline bool cmp(node x, node y)51 {52     return x.b == y.b ? x.a < y.a : x.b < y.b;53 }54 55 inline int query(int x, int y, int now, int l, int r)56 {57     if(x <= l && r <= y) return minn[now];58     if(l > y || r < x) return INF;59     push_down(now, r - l + 1);60     int mid = (l + r) >> 1;61     return std::min(query(x, y, ls), query(x, y, rs));62 }63 64 inline void update(int x, int y, int now, int l, int r)65 {66     if(x <= l && r <= y)67     {68         minn[now]--;69         add[now]--;70         return;71     }72     if(l > y || r < x) return;73     push_down(now, r - l + 1);74     int mid = (l + r) >> 1;75     update(x, y, ls);76     update(x, y, rs);77     push_up(now);78 }79 80 int main()81 {82     int i, j;83     scanf("%d %d", &n, &m);84     build(root);85     for(i = 1; i <= m; i++)86     {87         scanf("%d %d", &p[i].a, &p[i].b);88         if(p[i].a > p[i].b) swap(p[i].a, p[i].b);89     }90     std::sort(p + 1, p + m + 1, cmp);91     for(i = 1; i <= m; i++)92         if(query(p[i].a, p[i].b, root) > 0)93             ans++, update(p[i].a, p[i].b, root);94     printf("%d", ans);95     return 0;96 }