奇怪的错误

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<cmath>
#include<vector>
using namespace std;
int n,Min,num,now,m,x;
char ch[1];
vector<int> rank;
int main(){
    scanf("%d%d",&n,&Min);
    while(n--){
        scanf("%s%d",ch,&x);
        if(ch[0]=='I'){
            if(x<Min)
                continue;
            m++;
            x-=now;
            rank.insert(lower_bound(rank.begin(),rank.end(),x),x);
        }
        else
        if(ch[0]=='A')
            now+=x;
        else
        if(ch[0]=='S'){
            now-=x;
            while(num<m&&rank[num]+now<Min)
                num++;
        }
        if(ch[0]=='F'){
            if(x<=m-num)
                printf("%d\n",rank[m-x]+now);
            else
                printf("-1\n");
        }
    }
    printf("%d\n",num);
    return 0;
}

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<cmath>
#include<vector>
using namespace std;
int n,Min,num,now,m,x;
char ch[1];
vector<int> rank;
vector<int>::iterator it;
int main(){
    scanf("%d%d",&n,&Min);
    while(n--){
        scanf("%s%d",ch,&x);
        if(ch[0]=='I'){
            if(x<Min)
                continue;
            m++;
            x-=now;
            rank.insert(lower_bound(rank.begin(),rank.end(),x),x);
        }
        else
        if(ch[0]=='A')
            now+=x;
        else
        if(ch[0]=='S'){
            now-=x;
            if(rank.empty())
                continue;
            it=lower_bound(rank.begin(),rank.end(),Min-now);
            if(it==rank.begin())
                continue;
            if(it==rank.end()){
                num+=m;
                m=0;
                rank.clear();
            }
            else{
                num+=it-rank.begin();
                m-=it-rank.begin();
                rank.erase(rank.begin(),it);
            }
        }
        else
        if(ch[0]=='F'){
            if(x<=m)
                printf("%d\n",rank[m-x]+now);
            else
                printf("-1\n");
        }
    }
    printf("%d\n",num);
    return 0;
}
可这个真的有区别吗？感觉stl好玄