同一个代码，c环境下45分，c++环境下AC，这是为啥？

#include<stdio.h>
#include<math.h>
typedef long long ll;
ll n,m,s,r=-1,l,minn=1e13+100;;
ll w[200100],v[200100],sw[200100],sv[200100],li[200100],ri[200100];
int main(){
    scanf("%lld%lld%lld",&n,&m,&s);
    for(int i=1;i<=n;i++){
        scanf("%lld%lld",&w[i],&v[i]);
        if(w[i]>r)r=w[i];
    }
    for(int i=1;i<=m;i++)scanf("%lld%lld",&li[i],&ri[i]);
    while(l<=r){
        ll ans=0,mid=(l+r)/2,s1;
        for(int i=1;i<=n;i++){
            if(w[i]>mid)sw[i]=sw[i-1]+1,sv[i]=sv[i-1]+v[i];
            else sw[i]=sw[i-1],sv[i]=sv[i-1];
        }
        for(int i=1;i<=m;i++){
            ans+=(sw[ri[i]]-sw[li[i]-1])*(sv[ri[i]]-sv[li[i]-1]);
        }
        s1=s-ans;
        if(s1>0)r=mid-1;
        else l=mid+1;
        s1=abs(s1);
        if(minn>s1)minn=s1;
    }
    printf("%lld\n",minn);
    return 0;
}